A

A

A accommodation; adenine; ampere; anode (anodal); anterior; axial; mass number.

A₂ aortic second sound (see heart sounds).

A_w water activity. Relative to food for human consumption it is an indication of the amount of water available in the food as a substrate for bacterial growth. An A_w of 1 means pure water and no chance of bacterial growth.

a- word element. [L.] without, not.

α alpha, small letter; first letter in the Greek alphabet.

(A-a) Po₂ alveolar–arterial oxygen tension difference.

A band filaments of myosin forming a dark (anisotropic) band in the sarcomere.

A CRASH PLAN the acronym for a triage system: A= airway; C= circulation; R= respiratory; A= abdomen; S= spine; H= head; P= pelvis; L= limbs; A= arteries and veins; N= nerves.

A fibers nerve fibers in nerve trunks and peripheral nerves which have the fastest rate of transmission of nervous impulses.

A-mode amplitude mode. See A-mode ultrasonography.

A–R–F sequence remodeling sequence of bone cell activity; means activation–resorption–formation.

A site see aminoacyl-tRNA binding site.

aa. pl. arteriae [L.] arteries.

āā [Gr.] ana (of each), in prescriptions.

AAALAC Association for Assessment and Accreditation of Laboratory Animal Care.

AAAS American Association for the Advancement of Science.

AaDo₂ alveolar-arterial oxygen tension difference.

AAFCO American Association of Feed Control Officials.

AA-MRSA animal-associated methicillin-resistant Staphylococcus aureus.

AA protein a product of α-globulin and the major protein component of reactive amyloid.

AAHA American Animal Hospital Association.

AALAS American Association of Laboratory Animal Science

aalveld alveld.

Aanes’ method surgical reconstruction after a third-degree perineal laceration in the mare. There are two stages: the first operation constructs a shelf between the rectum and the vagina, the second reconstructs the perineal body.

aardvark (Orycteropus afer) a medium-sized, pig-like animal from sub-Saharan Africa. They have a long snout, a massive body, spadelike claws and a short, sparse haircoat. They are gray-brown in color, nocturnal in habit, live in burrows and exist mainly on a diet of ants. Called also earth pig.

aardwolf (Proteles cristata) a small African carnivore, member of the family Hyaenidae, but unlike other hyenas they feed mainly on termites and carrion. They have yellow fur with black stripes, live in burrows and are active mainly at night.

AAUAAA sequence see polyadenylation.

AAVC American Association of Veterinary Clinicians.

AAVMC Association of American Veterinary Medical Colleges.

AAVSB American Association of Veterinary State Boards.

Ab antibody. Called also gamma globulin (γ). See immunoglobulin.

ab [L.] preposition, from.

ab- word element. [L.] from, off, away from.

abalone Haliotis.

a. viral mortality a viral disease of molluscs with a very high mortality rate. A disease notifiable to the OIE (see Table 22).

abamectin a mixture of avermectins derived from Streptomyces avermitilis.

abandoned patient 1. a patient whose owner cannot be located or is unwilling to take the patient away, sometimes as a result of their inability or refusal to pay for veterinary services provided.

2. legal term in Veterinary practice acts meaning to forsake entirely, to neglect or refuse to provide or perform legal obligations for the care and support of an animal, or to refuse to pay for treatment or other services without an assertion of good cause. Constitutes the relinquishment of all rights and claims by the client to such an animal.

abarticular [ab″ahr-tik′u-lr] not affecting a joint; away from a joint.

abarticulation [ab″ahr-tik″u-la′shn] a dislocation.

abasia [-ba′zh] inability to walk.

a.–astasia astasia–abasia.

a. atactica abasia with uncertain movements, due to a defect of coordination.

choreic a. abasia due to chorea of the limbs.

paralytic a. abasia due to paralysis.

paroxysmal trepidant a. abasia due to spastic stiffening of the limbs on attempting to stand. Called also spastic abasia.

spastic a. see paroxysmal trepidant abasia (above).

trembling a., a. trepidans abasia due to trembling of the limbs.

abattoir a British, European and Australasian term for a facility for the slaughter of animals for human food. In North America this is more comonly called a meat packing plant. Called also slaughterhouse.

a. fever see Q fever.

abaxial situated away from the axis of the body, limb or part.

abbokinase see urokinase.

Abbreviata a genus of nematodes in the subfamily Physalopterinae, parasites of reptiles (especially saurians) or more rarely in amphibians and primates.

ABC 1. aspiration biopsy cytology. 2. a mnemonic for Airway, Breathing, Circulation. See cardiopulmonary resuscitation. 3. antecedent, behavior, consequence. See three-term contingencies.

ABCDE a mnemonic for advanced life support measures: Airway, Breathing, Circulation, Drugs, and Electrical stimulation.

abdomen [ab′d-mn] the portion of the body between the thorax and the pelvis containing the abdominal cavity and abdominal organs. See also abdominal.

acute a. an acute intra-abdominal condition of abrupt onset, usually associated with pain due to inflammation, perforation, obstruction, infarction or rupture of abdominal organs, and usually requiring emergency intervention. Called also surgical abdomen.

gaunt a. decreased abdominal size.

surgical a. see acute abdomen (above).

abdominal [ab-dom′-nl] pertaining to, affecting or originating in the abdomen. See also abdominal paracentesis, abdominal sounds.

a. binding a wide bandage applied to the abdomen to raise intraabdominal pressure. Its primary purposes are (1) to limit the displacement of the diaphragm during thoracic compression of cardiopulmonary resuscitation, thereby raising intrathoracic pressures achieved and improving forward blood flow, and (2) to maintain blood volume in the central circulation during hemorrhagic shock.

a. breathing an abnormal form of respiratory movement in which the thorax is fixed and the inspiratory and expiratory movement of the lungs are carried out by the diaphragm and the abdominal muscles so that there are exaggerated movements of the abdominal wall.

a. cavity the body cavity between the diaphragm and the pelvis containing the abdominal organs.

a. enlargement may result from fluid effusions (transudate, exudate or blood), enlargement of viscera (neoplasia, dilatation, engorgement or physiological phenomena, e.g. pregnancy), intraabdominal masses or fat. Weakness of the abdominal wall usually results in a pendulous rather than enlarged abdomen.

A-1 Pig with distended abdomen due to rectal stricture causing marked distension of the large intestine.

a. hernia the abnormal protrusion of an organ or tissue through a defect (of traumatic or congenital origin) of the abdominal wall.

a. lavage see abdominal lavage.

a. muscle ischemia an unexplained ischemic necrosis of the internal oblique muscle of ewes in late pregnancy which are carrying twins or triplets. Results in ventral hernia but often with little apparent effect on the ease of lambing.

a. muscles the paired muscles of the flank and belly that surround and support the abdominal viscera; made up of the internal and external abdominal obliques, the rectus and the transverse abdominis. See abdominal wall (below).

a. pad see abdominal pad.

a. pain may arise from an abdominal organ, the peritoneum or be referred as from spinal nerves.

a. regions arbitrary, descriptive subdivisions of the abdomen made up of three groups of three (like a noughts-and-crosses grid), three along the middle—xiphoid, umbilical and pubic, and three lateral pairs—hypochondriac, lateral abdominal and inguinal.

a. silhouette the shape of the abdomen viewed from behind.

a. trier see trier.

a. tunic see tunica flava abdominis.

a. viscera the organs contained within the abdominal cavity; they include the stomach, intestines, liver, spleen, pancreas, and parts of the urinary and reproductive tracts.

a. wall the fibro-muscular sheet that encloses the abdominal organs; its deepest layer consists of the parietal peritoneum, the deep and superficial layers of fascia, the transverse abdominal, internal and external abdominal oblique muscles, the subcutaneous tissue and finally the skin. It contains the linea alba and the umbilicus, the cicatrix marking the entry point of the umbilical cord, and is traversed by the inguinal canal, and at its caudal extremity carries the prepubic tendon, the ventral attachment of the wall to the pubic bones.

a. wall rigidity reflex response to pain of peritonitis, accompanied by pain on palpation or percussion.

abdominal sounds [ab-dom′-nl soundz] sounds heard on auscultation of the abdomen.

abdomin(o)- word element, abdomen.

abdominocentesis [ab-dom″-no-sen-te′sis] paracentesis of the abdomen. See also abdominal paracentesis.

abdominohysterotomy [ab-dom″-no-his″tr-ot′-me] hysterotomy through an abdominal incision.

abdominoparacentesis [ab-dom″-no par″-sen-te′sis] abdominocentesis.

abdominoscope [ab-dom″-no skōp] an endoscope that, by passage through the abdominal wall into the abdominal cavity, permits direct visualization of the abdomen and its contents. See also laparoscope.

A-2 A needle is slowly introduced into the peritoneal cavity on midline 2–3 cm caudal to the umbilicus for abdominocentesis.

From Taylor SM, Small Animal Clinical Techniques. Saunders 2010.

abdominoscopy [ab-dom″-nos′k-pe] examination of the abdomen and its contents with an endoscopic instrument inserted through the abdominal wall. See also laparoscopy.

abduce to abduct, or draw away.

abducens [ab-doo′snz] [L.] drawing away; pertaining to a movement away from the midline of the body.

a. nerve see abducent nerve, and Table 14.

abducent [ab-doo′snt] abducting.

a. nerve either of the paired sixth cranial nerves; each arises from the pons and supplies the lateral rectus and retractor bulbi muscles of the eye, allowing for motion. Paralysis of the nerve causes a medial strabismus and absence of third eyelid protrusion when the corneal reflex is tested. See also Table 14.

abduct [ab-dukt′ ] to draw away from an axis or the median plane.

abduction [ab-duk′shn] the act of abducting; the state of being abducted. For a digit, the drawing away from the axis of the limb.

abductor [ab-duk′tor] that which abducts.

Aberdeen Angus a black, polled, popular breed of beef cattle that originated in the counties of Aberdeen and Angus in NE Scotland. It is considered by many to have major advantages over other beef breeds in desirable carcass characteristics and was arguably the first breed to have a branded beef program (certified Angus beef®).

aberrant pigment metabolism [ă-ber′nt pig′mnt m-tab′-liz″m] see inherited porphyria.

aberration [ab″r-a′shn] 1. deviation from the normal or usual. 2. imperfect refraction or focalization of a lens, e.g. the lens of the eye.

chromatic a. color distortion in an image caused by the inability of the lens to bring the various colors of light to focus at a single point due to their different refrangibility. In an optical instrument such as a microscope this represents an error in the lens system.

spherical a. defocused image due to light from the margin of a spherical lens coming to a shorter focus than light from the central portion. In an optical instrument this represents a fault in construction.

Abildgaard method named after P.C. Abildgaard, a Danish veterinarian; a method of casting horses and cattle. The horse method is a combination of sidelines and hobbles in which all four feet are included in a rope and harness system which brings all four hooves up to the belly. The cattle method is also one in which all four hooves are trapped and pulled together, but they are not brought up to the midline. The harness is made entirely of rope.

abiosis [a″bi-o′sis] absence or deficiency of life.

abiotrophic disease [a″bi-o-tro′fik] see abiotrophy.

abiotrophy [a″bi-ot′r-fe] inherited developmental defect resulting in a lack of a biologic substance within a cell type which is necessary for the maintenance of that cell and which leads to premature degeneration.

cerebellar a. occurs in Arabian horses, cattle, pigs and dogs. Affected young are normal at birth but at an early age ataxia and signs of cerebellar dysfunction appear, often progressing to complete immobilization. Cerebral function is usually normal. An inherited basis is suspected. In Kerry blue terriers, it is inherited as an autosomal recessive trait. Called also cerebellar neuronal abiotrophy.

cochlear a. an inherited degeneration of the cochlear duct of dogs causing deafness which becomes evident after several weeks of age.

hereditary neuronal a. of Swedish Lapland dogs an autosomal recessive trait with lower motor neuron abiotrophy causing arthrogryposis, tetraplegia and muscle atrophy from 5 weeks of age.

spinal cord a. see hereditary neuronal abiotrophy of Swedish Lapland dogs (above).

abirritant 1. diminishing irritation; soothing. 2. an agent that relieves irritation.

abirritation [ab-ir--ta′shn] diminished irritability; atony.

ablactation [ab″lak-ta′shn] weaning.

ablastin [a″blas′tin] an antibody that inhibits the reproduction of some protozoan parasites.

ablate [ab-lāt′] to remove, especially by surgical means.

ablatio [ab-la′she-o] [L.] detachment.

a. retinae detachment of the retina.

ablation [ab-la′shn] 1. separation or detachment; extirpation; eradication. 2. removal, especially by cutting.

ear canal a. a surgical procedure in which the cartilaginous external ear canal is removed. Indicated in neoplasia of the canal or chronic otitis externa in dogs which are unresponsive to all other forms of treatment.

scrotal a. removal of the scrotal sac, usually because of trauma or neoplasia or in association with scrotal urethrostomy.

subconjunctival a. a method of removal or enucleation in which the globe is removed leaving the conjunctiva.

ablepharia [a″bl-far′e-] congenital absence of the eyelids.

ablepharon [a″blef′-ron] see ablepharia.

abluent [ab′loo-nt] 1. detergent; cleansing. 2. a cleansing agent.

abnormality [ab″nor-mal′-te] 1. the state of being unlike the usual condition. 2. a malformation.

inherited a. a defect of anatomy or function acquired by the patient from its parents by way of inherited material passed through the germ cells from which the patient originated. See also inheritance.

abnutzen pigment see lipofuscin.

abomasal [ab″o-ma′sl] pertaining to, affecting or originating from the abomasum.

a. anterior displacement syndrome in cattle in which the abomasum is displaced anteriorly to a position between the reticulum and the diaphragm; characterized clinically by anorexia, ketonuria, and absence of abomasal sounds in the right or left flanks as in right or left displacement.

a. atony lack of tone of abomasal wall, thought to be basic cause of displacements and torsion. Possibly due to prolonged feeding on finely ground concentrates.

a. bloat distention of abomasum with gas produced by fermentation of milk in abomasum of young ruminants, especially artificially reared lambs fed large volumes of warm milk infrequently. See Sarcina-like organisms.

a. dilatation see right abomasal displacement (below).

a. displacement see left abomasal displacement, right abomasal displacement (below).

a. emptying defect wasting disease of long clinical course and poor prognosis, particularly in Suffolk sheep, in which the defining feature is a markedly distended and impacted abomasum. Possibly an acquired form of dysautonomia.

a. fundus the cranial blind end of the abomasum, lying over the xiphoid process of the sternum and to the right of the reticulum; not readily distinguished from the body of the abomasum (corpus abomasi). Called also fundus abomasi.

a. gastrocentesis cannulation of a distended abomasum, usually through the right flank, to allow evacuation of the distending gas. The technique may be used for diagnostic reasons, but is more commonly used therapeutically to gain temporary relief for the animal before surgery is undertaken.

a. groove the third and last part of the gastric groove of ruminants that occupies the lesser curvature of the abomasum and which is free from mucosal folds. See also gastric groove. Called also sulcus abomasi.

a. impaction a disease of beef cows with large energy requirements, e.g. during very cold weather or when fed poor quality roughage with low energy content and poor digestibility. The abomasum impacts with dry roughage and the abdomen distends on the right; clinical signs are scant feces and emaciation.

left a. displacement chronic disease of high producing, recently calved cows with anorexia, ketosis and abdominal gauntness and characterized by a distended abomasum trapped under the rumen, detectable on the left side by poorly audible reticulorumen movements and the presence of a ping on percussion over the left paralumbar fossa and cranial to it. Fatty liver and abomasal ulcers are possible complications. Corrected by surgical methods.

a. perforation may be perforation by erosion through a preexisting ulcer, or by rupture along the greater curvature due to dilatation. Perforation results in acute or peracute peritonitis; rupture is followed by sudden death. See also abomasal ulcer (below).

a. phytobezoar see phytobezoar.

a. reflux the reflux of fluid from the abomasum into the rumen that occurs when flow to the intestine from the abomasum is obstructed. Rumen chloride concentrations increase, there is a fall in the buffering capacity of the rumen and a hypochloremic, hypokalemic metabolic alkalosis. See also intestinal obstruction, pyloric obstruction.

right a. displacement a disease of recently calved cows characterized by anorexia, depression, absence of rumination, scant abnormal feces, distention of right abdomen, ping over right flank, and fluid splashing sounds on the ballottement of the right flank. Corrected by deflation of the abomasum or surgery. May terminate as abomasal volvulus.

a. rupture see abomasal perforation (above).

a. torsion see abomasal volvulus (below).

a. trichobezoar see trichobezoar.

a. tympany see abomasal bloat (above).

a. ulcer many calves have clinically silent ulcers during the period of change from a milk diet to one of fiber. In adult animals the ulcer may be hemorrhagic, with a sudden onset of subacute abdominal pain with alimentary tract stasis and heavily bloodtinged feces, or perforating. See abomasal perforation (above).

a. volvulus a disease of sudden onset in dairy cows, often following a subacute illness due to abomasal dilatation. There is shock, acute abdominal pain, distention of the right abdomen with sounds of fluid present, blood-stained feces and a fatal outcome in 24–48 hours.

abomasitis [ab″o-m-si′tis] inflammation of abomasum; occurs as part of many gastroenteritides but seldom diagnosed as a separate condition. The organ’s location aboral to the forestomachs provides some protection against dietary insults. Abomasitis caused by Clostridium sordelli is an emerging problem in sheep in Great Britain, manifest with sudden death. Lambs between 6 and 10 weeks are particularly at risk. See also abomasum.

abomasopexy [ab″o-ma’so-pek″se] fixation of the replaced abomasum, after correction of a displacement, by suturing the abomasal wall or its attached omentum to the abdominal wall. See also omentofixation.

abomasotomy [ab″o-ma-sot’-me] surgical opening of the abomasum, usually to remove impacted food or foreign material, especially phytobezoars.

abomasum [ab″o-ma’sum] the fourth and glandular compartment of the ruminant stomach. It is an elongated sac, comparable in structure and function to the simple stomach of nonruminants. It lies in the right half of the abdominal cavity, largely on the abdominal floor, except in late pregnancy when it is pushed cranially by the enlarging uterus and may also be lifted from the abdominal floor. See also abomasal, forestomachs.

Abondance cattle French breed of dual-purpose cattle, mostly red, some red on belly and extremities.

aborad [ab-or’ad] away from the mouth; aborally. A useful term to describe a location along the digestive tract when terms like cranial and caudal are inappropriate. See also orad.

aboral [ab-or’l] away from the mouth.

abort [-bort’ ] 1. to arrest prematurely a disease or developmental process. 2. to expel the products of conception before the fetus is viable.

abortifacient [-bor″t-fa’shnt] 1. causing abortion. 2. an agent that induces abortion.

abortion [-bor’shn] premature expulsion from the uterus of the products of conception; termination of pregnancy before the fetus is viable.

artificial a. voluntary or elective termination of pregnancy. See also parturition induction.

campylobacter a. see infectious abortion (below).

complete a. complete expulsion of all the products of conception.

early a. abortion within the first third of pregnancy. Defined also as an early pregnancy loss (EPL), early embryo loss (EEL) or early embryonic death (EED). In cattle and horses most of these losses occur in the first 50–60 days of pregnancy.

epizootic bovine a. characterized by serious fetal disease followed by abortion or birth of weak calves. Endemic in California’s coastal range and in the foothill region of the Sierra Nevada, USA. Necropsy findings in the fetus are diagnostic; they include profuse petechiation and severe granulomatous hepatitis. Cause appears to be a novel deltaproteobacterium closely related to members of the order Myxococcales. Transmitted by the tick, Ornithodoros coriaceus. Called also foothill abortion.

habitual a. spontaneous abortion occurring in three or more successive pregnancies. An inherited disorder of older Angora goats which is the result of adrenal malfunction. Goats abort around 100 days of pregnancy. Affected does have fine hair coats and high yield. Also described in alpacas as a result of low circulating progesterone.

incomplete a. abortion in which parts of the products of conception are retained in the uterus.

induced a. abortion procured by the veterinarian to eliminate a misalliance, to reduce wastage in animals in a feedlot, to encourage commencement of lactation earlier than would otherwise occur. In large animals (equine and bovine), manipulation through the rectal wall is a possible way of destroying the viability of the fetus. Induction by the administration of prostaglandins or corticosteroids is more usual. See also pregnancy termination.

infectious a. the common causes in the various species are: CATTLE: Brucella abortus (brucellosis); Campylobacter fetus subsp. venerealis (bovine genital campylobacteriosis); Campylobacter fetus subsp. fetus; Leptospira pomona, L. hardjo (leptospirosis); Listeria monocytogenes (listeriosis); Arcanobacterium pyogenes; Aspergillus, Lichtheimia and Mucor spp. (fungal abortion); bovine virus diarrhea virus; infectious bovine rhinotracheitis herpesvirus; Chlamydophila abortus; a deltaproteobacterium (epizootic bovine abortion); Coxiella burnetii (Q fever), Neospora caninum. SHEEP AND GOATS: Campylobacter fetus subsp. fetus; Campylobacter jejuni; Chlamydophila abortus (enzootic abortion of ewes); Listeria monocytogenes (listeriosis); Salmonella abortus-ovis; Brucella melitensis; Toxoplasma gondii (toxoplasmosis); Brucella ovis (limited occurrence); bluetongue virus; border disease, Coxiella burnetti (Q fever). HORSES: Streptococcus equi subsp zooepidemicus; Actinobacillus equuli, A. equisimilis; Crossiella equi, Rhodococcus equi; leptospirosis, most commonly the pomona serogroup and less frequently serovar grippotyphosa; equine herpesvirus (EHV1); equine viral arteritis (EVA); equine arteritis; Potomac horse fever; and in the USA the mare reproductive loss syndrome associated with ingestion of the Eastern tent caterpillar Malacosoma americanum. PIGS: Leptospira pomona, L. grippotyphosa, L. canicola, L. icterohaemorrhagiae (leptospirosis); Erysipelothrix rhusiopathiae (erysipelas); porcine reproductive respiratory syndrome (PRRS) virus; parvovirus; porcine circovirus 2; Aujesky’s disease; classical swine fever; and African swine fever. CAMELIDS: Campylobacter fetus subsp. fetus (vibriosis); Chlamydophila abortus; Listeria monocytogenes (listeriosis); Brucella melitensis, B. abortus, Toxoplasma gondii (toxoplasmosis); bovine virus diarrhea virus; Leptospira spp.; Neospora caninum; Coxiella burnettii (Q fever); Streptococcus equi subsp. zooepidemicus. DOGS AND CATS: Brucella canis, feline leukemia virus, feline herpesvirus.

missed a. the animal was diagnosed pregnant, but found later to be open.

pine needle a. a late-term abortion with retained fetal membranes in cattle caused by ingestion of isocupressic acid in the needles of Pinus spp., commonly P. ponderosa, but also P. jeffryi, P. contorta and Juniperus scopulorum and J. communis. Nutrient deficiency and tree management practices may promote ingestion off the ground as cattle graze through while eating early growing spring grass.

a. rate number of abortions as a percentage of the cows in the herd which were diagnosed pregnant in early pregnancy; the target is less than 2% but rates commonly approach 8% in dairy cattle and 5% in beef cattle.

septic a. abortion associated with serious infection of the uterus leading to generalized infection.

spontaneous a. abortion occurring naturally. See also spontaneous abortion.

a. storm a cluster of abortions occurring at about the same time or in rapid sequence within a group of pregnant females. See also equine viral abortion.

therapeutic a. abortion induced by a veterinarian for medical or other health reasons.

abortive [-bor’tiv] 1. incompletely developed. 2. abortifacient.

abortus [-bor’ts] a dead or nonviable fetus.

ABP see androgen binding protein.

ABPEE acronym for acute bovine pulmonary emphysema–edema. See atypical interstitial pneumonia.

ABR auditory brainstem response.

ABR test abortus-bang-ring test. See also brucellosis testing, milk ring test.

abrachia [-bra’ke-] congenital absence of the forelimbs.

abrachiocephalia [-bră″ke-o-s-fa’le-] acephalobrachia.

abrasion [-bra’zhn] a wound caused by rubbing or scraping the skin or mucous membrane. A ‘skinned knee’ and a ‘rope burn’ are common examples.

dental a. abnormal wearing away of tooth substance caused by mechanical process such as chewing of rocks or metal cages. Compare with dental attrition.

abrasive [-bra’siv] 1. causing abrasion. 2. an agent that produces abrasion.

abrin [a’brin] lectin or toxalbumin consisting of two peptide chains linked by a disulfide bridge in the seeds of Abrus precatorius. Causes gastroenteritis, liver necrosis and sometimes convulsions.

Abrus [a’brs] pantropical plant genus of the legume family Fabaceae.

A. precatorius seeds contain a toxin, abrin, which causes gastroenteritis, liver necrosis and convulsions. Dogs have been poisoned by chewing on necklaces and jewelry made from the seeds (beans). Called also jequirity, love precatory, lucky or paternoster bean, rosary or coral pea, crab’s eye, minnie-minnie, Indian liquorice.

abscess [ab’ses] a localized collection of pus in a cavity formed by the disintegration of tissue. Most abscesses are formed by invasion of tissues by bacteria, but some are caused by fungi or protozoa or even helminths, and some are sterile. They are usually separated from parent tissue by a fibrous tissue capsule, and are examples of chronic inflammation. For specific abscesses see under anatomical sites, e.g. brain abscess.

apical a. a localized suppurative inflammation of tissues about the apex of a tooth root.

Brodie’s a. a circumscribed abscess in bone, caused by hematogenous infection that becomes a chronic nidus of infection.

cervical a. see vertebral abscess.

cold a. one of slow development, little local irritation and hence minimal fibrous encapsulation, e.g. caseous lymphadenitis of sheep and goat.

cornea stromal a. abscesses within the corneal stroma due to bacteria or fungi which gain entry through ulcers or punctures that subsequently re-epithelialize. Particularly important in horses.

diffuse a. a collection of pus not enclosed by a capsule. More properly described as cellulitis.

facial subcutaneous a. a disease of cattle eating hay or pasture containing mature grass awns.

gas a. one containing gas, caused by gas-forming bacteria such as Clostridium perfringens.

grass seed a. in cattle occurs as a subcutaneous abscess at the throat or on the mandible and is often diagnosed but rarely confirmed. In dogs it occurs in many sites, but most commonly between the toes. The causative grass awn(s) may be recovered by forceps or, in more extensive lesions, surgical exploration.

hepatic a. abscess of the liver caused by a variety of infectious agents.

infraorbital a. occurs in birds as a sequel to chronic upper respiratory infection with sinusitis.

injection site a. an iatrogenic lesion resulting from incomplete skin disinfection before injection; usually contains Arcanobacterium pyogenes and anaerobes in cattle, and commonly contain anaerobes in other species. Sterile abscesses can occur from reaction to the material injected, for example copper glycinate.

A-3 Potential routes of apical infectiion of equine maxillary cheek teeth.

From Dacre IT, Kempson S, Dixon PM: Pathological studies of cheek teeth apical infections in the horse: 5. Aetiopathological findings in 57 apically infected maxillary cheek teeth and histological and ultrastructural findings. Vet J 178:352-368, 2008. Elsevier.

internal abdominal a. see retroperitoneal abscess.

intra-abdominal a. include diaphragmatic, mesenteric, retroperitoneal; many are subclinical; clinical signs include those of chronic peritonitis. Called also omental bursitis.

maxillary a. see malar abscess.

mediastinal a. a very large abscess in this site may cause signs of congestive heart failure due to compression of pericardium and venae cavae.

miliary a. one of a set of small abscesses; the name derived from millet seed (size).

milk a. abscess of the mammary gland occurring during lactation.

pancreatic a. abscess of the pancreas, most commonly seen as a sequel to pancreatitis.

pectoral a. a disease of horses in which abscesses occur in the pectoral muscles and ventral midline, and in some cases in internal organs, causing local pain and swelling and eventually rupturing and draining to the exterior. Endemic to areas of California, Texas and Colorado in the USA where it is also known as pigeon fever and has epidemic occurrence in the autumn of some years with possible insect vector transmission. Caused by Corynebacterium pseudotuberculosis.

periapical a. inflammation and destruction of dental pulp and surrounding tissues, including the periodontal membrane and alveolar bone. The radiographic appearance is a translucency of the tooth apex and adjacent alveolar bone. Most common in dogs.

periorbital a. firm masses above or below the eyes occur in birds as a sequel to chronic respiratory disease and sinusitis.

phlegmonous a. one associated with acute inflammation of the subcutaneous connective tissue; more properly called cellulitis.

phoenix a. acute recurrence of a chronic periapical abscess.

primary a. one formed at the seat of the infection.

prostatic a. of the prostate galnd, most commonly seen in entire male dogs and commonly containing Escherichia coli, Proteus spp., staphylococci, streptococci and Pseudomonas.

rete mirabile a. see pituitary abscess.

retroarticular a. one located between the intermediate phalanx and the deep flexor tendon in the hooves of cattle. It may be caused by extension of infection from the navicular bursa or from suppurative arthritis of the distal interphalangeal joint.

A-4 Miliary abscesses in the liver of a near-term aborted lamb.

A-5 Pectoral abscess (pigeon fever) with swelling of the left pectoral region and the lower neck.

From McAuliffe SB, Slovis NM, Color Atlas of Diseases and Disorders of the Foal. Saunders, 2008

retrobulbar a. abscess within the orbit behind the globe; causes pain on opening of the mouth, chemosis and exophthalmos, protrusion of the nictitating membrane, and sometimes systemic signs of infection. Most common in dogs and cats.

stitch a., suture a. one developed about a stitch or suture.

vertebral body/epidural a. usually of cervical or lumbar vertebrae; causes compression of the spinal cord resulting in clinical signs of pain, ataxia and paresis.

wandering a. one that escapes from its fibrous capsule, tracks through adjacent tissue and may discharge at a distance from the site of origin.

abscessation formation of an abscess.

abscise to cut off or remove.

abscissa [ab-sis’] the distance of the x-coordinate along the horizontal or x-axis from the vertical or y-axis in a rectangular coordinate system. Also, now commonly used as an alternate term for the horizontal or x-axis of a graph.

abscission [ab-s’zhn] removal of a part or growth by cutting.

abscopal [ab-sko’pl] pertaining to the effect on nonirradiated tissue resulting from irradiation of other tissues of the body.

Absidia see Lichtheimia.

absorb [ab-sorb’] 1. to take in or assimilate, as to take up substances into or across tissues, e.g. the skin or intestine. 2. to stop particles of radiation so that their energy is totally transferred to the absorbing material.

absorbance [ab-sor’bns] in radiology, a measure of the ability of a medium to absorb radiation, expressed as the logarithm of the quotient of the intensity of the radiation entering the medium divided by that leaving it.

absorbefacient [ab-sor″b-fa’shnt] 1. causing absorption. 2. an agent that promotes absorption.

absorbent [ab-sor’bnt] 1. able to take in, or suck up and incorporate. 2. a tissue structure, lymphatic or other vessel, involved in absorption. 3. a substance that absorbs or promotes absorption. Absorbents used pharmaceutically are usually finely ground inert substances applied locally to prevent friction and reduce tissue irritation, e.g. talc, zinc stearate, amixture of boric acid and calciumoxide. Similar substances, e.g. finely ground charcoal, kaolin, are administered orally for the same purposes and also to absorb toxins.

absorption [ab-sorp’shn] 1. the act of taking up or in by specific chemical or molecular action; especially the passage of liquids or other substances through a surface of the body into body fluids and tissues, as in the absorption of the end products of digestion into the villi that line the intestine. 2. in radiology, uptake of energy by matter with which the radiation interacts.

chemical a. any process by which one substance in liquid or solid form penetrates the surface of another substance.

Compton a. effect see Compton effect.

differential a. the difference in the absorption of X-rays by different tissues.

digestive a. the passage of the end products of digestion from the gastrointestinal tract into the blood and lymphatic vessels and the cells of tissues. Absorption of this kind can take place either by diffusion or by active transport.

percutaneous a. absorption of drugs or noxious substances through the skin.

radiation a. the dissipation of radiant energy as it passes through matter. This phenomenon is of particular importance in diagnostic and therapeutic radiology, which depends on the interaction between ionizing radiations and matter. As radiation passes through matter, it is absorbed by an amount dependent on the atomic and molecular structure and thickness of the substance, and the energy of the primary photons. If radiations pass through a medium of living or nonliving material without absorption (loss of energy), no biological or photographic effects can occur. In true absorption the photons of radiation waves give up or transfer all of their energy to electrons within the atoms of the matter through which they are passing.

a. tests are used to assess absorptive function of the small intestine. Glucose, D-xylose and fats are substances administered orally and at timed intervals later measured in the blood. See also digestive absorption (above), fat absorption test.

absorptive [ab-sorp’tiv] having the power of absorption; involving absorption.

abtorsion [ab-tor’shn] outward rotation of the globe around the line of sight when the eye is at its central primary position.

abu nini [Sudanese] see contagious caprine/ovine pleuropneumonia.

abuse [-būs’] misuse, maltreatment or excessive use.

animal a. a modern day concept by which the trust that animals should have in humans, in return for the benefits that they bestow, is betrayed when humans abuse animals physically or psychologically. The abuses often stop short of cruelty in a legal sense but can be classified as harassment. The term has a variable but generally wide scope and includes physical cruelty by assault, by deprivation of adequate food, water, transport and shelter, and proper care during illness, pregnancy and parturition, and participation in sporting events at a level beyond the animal’s capacity to perform. This form of abuse covers such misuses as excessively arduous endurance rides, ignominious performances and exhibits, oppressive displays of obedience. Mental or psychological abuse is less readily defined but in today’s culture is usually taken to include undue confinement, demeaning performance as entertainment and harassment by teasing.

ABVP American Board of Veterinary Practitioners.

Abyssinian 1. a mediumhaired breed of domestic cat with yellow or green eyes and a characteristic coat that results from the double or triple bars of pigmentation (agouti ticking) on individual hairs giving an appearance similar to that of a hare. The breed is affected by amyloidosis and retinal atrophy. 2. a variety of guinea pig with harsh coat that forms swirls and rosettes.

Ac chemical symbol, actinium.

a.c. [L.] ante cibum (before meals).

Acacia [-ka’sh] a large genus of trees and shrubs of warm, dry regions, belonging to the legume family Mimosaceae, which provides valuable browse for grazing ruminants but also contains some poisonous plants. About 5% of Australian Acacia spp. are cyanogenic. Acacia spp. capable of causing cyanide poisoning: A. atkinsiana, A. binerva (A. glaucescens), A. blakei, A. burrowii, A. caffra, A. caroleae, A. cheelii (motherumbah), A. concurrens (A. cunninghamii), A. conniana (A. cognata), A. crassa (A. cunninghamii), A. cunninghamii (black wattle), A. curvinervia, A. deanei (A. paucijuga), A. doratoxylon, A. erioloba (camel thorn), A. exilis, A. glaucescens (sally wattle), A. granitica, A. gregii (catclaw), A. lasiocalyx, A. lasiopetala (A. sieberana), A. leiocalyx (A. melanoxylon), A. longifolia, A. longispicata (A. cunninghamii), A. olgana, A. osswaldii, A. polybotrya, A. pulchella, A. pycnostachya, A. schinoides, A. sibina, A. sieberana, A. sparsiflora, A. sutherlandii (A. melaleucoides), A. yorkrakinensis.

A. aneura Called also mulga. See acquired melanosis.

A. berlandieri contains tyramine which causes ataxia in sheep and goats. Called also guajillo.

A. cana can accumulate selenium if the soil selenium content is unusually large.

A. catechu cyanogenic plant. See catechu.

A. erioloba host plant of Gonometa spp. (molopo moth); the moth larva produces indigestible silk in its cocoon; causes rumen impaction; a South African phenomenon.

A. georginae has a high concentration of fluoroacetate and can cause sudden death. Called also Georgina gidgee or Georgina gidyea.

A. melanoxylon contains toxic tannins; rarely causes ataxia, recumbency, alimentary tract irritation.

A-6 Abyssinian guinea pig.

From Mitchell M, Manual of Exotic Pet Practice. Saunders 2009

A. mellifera host plant for Gonometa spp. (molopo moth), the larva of which produces indigestible silk in its cocoon; causes ruminal impaction.

A. nilotica subsp. kraussiana pods contain toxins which cause hemolysis, methemoglobinemia and diarrhea.

A. salicina contains toxic tannins; rarely causes incoordination, recumbency.

acacia [-ka’sh] 1. general term for the very large number of species of shrubs and trees in the genus Acacia; many known also generally as wattles in Australia. 2. the dried exudate from Acacia senegal and other Acacia species of African origin, used as an emulsifier, stabilizer and suspending agent. Called also gum arabic and gum acacia.

false a., black a. see Robinia pseudoacacia.

academic associates extramural instructors appointed by universities who have much experience in the vocational aspects of veterinary science. Undergraduate and postgraduate students are sent to the practices of these veterinarians to acquire practical experience which may not be available over the whole scope of the profession’s interests at the university. See also seeing practice.

academic education education in the principles of the subject or course. In veterinary science this includes anatomy, physiology, biochemistry, pharmacology, nutrition, genetics, general pathology, microbiology and parasitology, epidemiology and the disciplines in medicine and surgery and theriogenology. Complemented by vocational education aimed at the more practical aspects of the profession.

ACAID anterior chamber-associated immune deviation

acampsia [-kamp’se-] rigidity of a part or limb.

acantha [-kan’th] thorn[Gr.]; a spine-like structure.

acanthamebiasis [acan˙tha˙me˙bi˙a˙sis] infection by amebae of the genus Acanthamoeba; has been observed rarely in dogs.

Acanthamoeba [-kan″th-me’b] free-living amebae that can cause pneumonia, general systemic infection and encephalomyelitis in animals and humans.

acanth(o)- word element. [Gr.] sharp spine, thorn.

Acanthocephala [-kan″tho-sef’-l] a phylum of elongate, mostly cylindrical organisms (thorny-headed worms) parasitic in the intestines of all classes of vertebrates.

acanthocephalans [-kan″tho-sef’-lns] members of the phylum Acanthocephala.

acanthocephaliasis [-kan″tho-sef″-li’-sis] disease caused by infection with members of the phylum Acanthocephala.

acanthocephalid see acanthocephalans.

Acanthocephalus [-kan″tho-sef’-ls] a genus of thorny-headed worms of the family Echinorhynchinae. Includes A. jacksoni (in trout).

Acanthocheilonema reconditum [-kan″tho-ki″lo-ne’m] found in body cavities and connective tissue of dogs. Called also Dipetalonema reconditum.

acanthocyte [-kan’tho-sīt] an erythrocyte with protoplasmic projections giving it a thorny appearance; results from intravascular erythrocyte fragmentation associated with microangiopathy. Most commonly seen in dogs vasculitis or other vascular anomalies, hemangiosarcomas or liver disease. Morphologically similar to spur cells, but biochemically distinct.

acanthocytosis [-kan″tho-si-to’sis] the presence in the blood of acanthocytes.

A-7 Acanthamoeba trophozoites from culture. Note the filamentous pseudopods and the large central karyosome within the nucleus. From Bowman DD, Georgis’ Parasitology for Veterinarians, 9th Edition. Saunders, 2008

acantholysis [ak″an-thol’-sis] loss of cohesion between epidermal cells, resulting in intraepidermal clefts, vesicles and bullae. Seen in inflammatory, viral, heritable and autoimmune skin diseases, particularly the pemphigus complex.

a. bullosa see epidermolysis bullosa.

familial a. a congenital disease of Aberdeen Angus calves and lambs characterized by ulceration of the oral mucosa and the skin over the distal limb joints and the coronet and loss of claws with minor trauma.

acanthoma [ak″an-tho’m] a tumor in the prickle cell layer of the skin. See intracutaneous cornifying epithelioma.

infundibular keratinizing a. see intracutaneous cornifying epithelioma.

Acanthophis [-kan’tho-fis] the genus of death adders; includes A. antarcticus (common death adder) and A. pyrrhus (desert death adder).

acanthor larva contained within the mature eggs of acanthocephalans; the egg is thick-shelled and the larva carries an anterior circlet of hooks and spines.

acanthosis [ak″an-tho’sis] an increased thickness of the stratum spinosum, due to either an increased number or hypertrophy of cells.

frictional a. see acanthosis nigricans (below).

a. nigricans a skin disease of dogs, characterized by hyperpigmentation, lichenification, seborrhea, and alopecia commencing in the axillae and often spreading to involve flexural surfaces of all limbs, and the ventral body. Dachshunds are particularly predisposed to primary acanthosis, often developing the first changes at a young age. Sporadic cases are secondary to systemic disease, endocrinopathies, hypersensitivity reactions and friction in body folds.

Acanthospermum plant genus of the Asteraceae family; originated in tropical America.

A. hispidum capable of causing nitrate-nitrite poisoning. May contain a hepatotoxin. Called also star burr.

Acanthospiculum [ak″an-tho spik’u-lm] see Onchocerca.

acapnia decrease of carbon dioxide in the blood.

acarapisosis a disease of the adult honey bee (Apis mellifera) and possibly other Apis species caused by the honey bee tracheal mite Acarapis woodi, which parasitizes the respiratory system resulting in moderate to high mortality. A disease notifiable to the OIE (see Table 22).

acarbia [a-kahr’be-] decrease of bicarbonate in the blood.

acarbose [a’kahr-bōs] an alpha-glucosidase inhibitor which reduces postprandial hyperglycemia. It has been used in the management of diabetes mellitus.

acardia [a-kahr’de-] a developmental anomaly with absence of the heart.

acardiacus [a″kahr-di’-kus] [L.] having no heart.

acardius [a-kahr’de-us] an imperfectly formed twin fetus without a heart and invariably lacking other body parts.

acariasis [ak″-ri’-sis] infestation with arthropod parasites of the order Acarina including the ticks and mites. See also tick infestation.

cutaneous a. see mange.

A-8 Acanthosis nigricans in the axillae of a 1-yearold Dachshund.

nasal a. see nasal acariasis.

oto-a. see Otodectes cynotis.

otodectic a. see Otodectes cynotis.

pulmonary a. see Pneumonyssoides.

acaricide [-kar’-sīd] an agent that destroys ticks and mites. The common ones are the organophosphorus compounds, the synthetic pyrethroids, the carbamates and the macrocyclic lactones. The chlorinated hydrocarbons are no longer much used on farm animals because of the problems with residue in tissues.

acarid [ak’-rid] a tick or a mite of the order Acarina.

Acarina [ak″-ri’n] an order of arthropods (class Arachnida), including mites and ticks.

acarine [ak’-rīn] pertaining to or of the nature of members of the order Acarina, including the ticks and mites.

acarinosis [-kar″-no’sis] any disease caused by mites.

acarodermatitis [ak″-ro-dur″m-ti’tis] skin inflammation due to bites of parasitic mites (acarids).

Acaroidea a superfamily of the order Acarina.

Acarus [ak’-rus] a genus of free-living mites, including A. farinae, A. longion, A. siro and A. tawinae; see Tyroglyphus.

acaryote 1. non-nucleated. 2. a non-nucleated cell.

ACAT acyl CoA:cholesterol acyltransferase; an important enzyme responsible for the esterification of cholesterol with long chain fatty acids, a reaction that removes the inhibitory influence of free cholesterol on activity of HMG CoA reductase and the synthesis of LDL receptors.

accelerated conduction syndrome see accessory tract atrioventricular conduction.

accelerator [ak-sel’r-a″tr] [L.] an agent or apparatus that increases the rate at which something occurs or progresses.

developing a. alkaline constituent of an X-ray developer which controls the rate of development. Called also activator.

a. factor, a. globulin factor V, one of the blood clotting factors. Called also proaccelerin, labile factor.

linear a. very high energy (1–20 mega volt) X-ray machine to administer radiation therapy treatment.

serum prothrombin conversion a. (SPCA) clotting factor VII; see proconvertin.

acceptability of food the measure of whether an animal will consume enough of a food to meet its caloric needs.

acceptable daily intake the amount of a drug or chemical residue to which an animal can be exposed daily for a lifetime without suffering a deleterious or injurious effect, on the basis of all of the facts known at the time.

acceptance sampling statistical quality control method to determine the quality of a product by sampling a small portion of it. Reduces the likelihood of acceptance of a defective product.

acceptor [ak-sep’tr] a substance that unites with another substance.

hydrogen a. the molecule accepting hydrogen in an oxidation–reduction reaction.

access [ak’ses] surgical term for the ease of reaching the target organ or site in an operation.

accessory [ak-ses’-re] supplementary or affording aid to another similar and generally more important thing.

a. nerve see Table 14.

a. sex glands any gland, other than the gonad, associated with the genital tract, such as the ampulla of the ductus deferens, the bulbourethral, prostate and vesicular glands of the male. The term is usually restricted to the male. Called also glandulae genitales accessoriae.

Accipiter genus of birds of prey that includes goshawks and sparrowhawks.

acclimation [ak″l-ma’shn] the process of becoming accustomed to a new environment.

acclimatization [-kli″m-t-za’shn] the adaptation of an animal to the climatic conditions in an area. The ability to adapt in this way is an important characteristic of livestock.

accommodation [-kom″-da’shn] adjustment, especially rapid adjustment, of the eye for focusing on objects at various distances. Accomplished by the ciliary body muscles, which (depending on species) alter lens position or shape, globe length, or corneal radius of curvature as needed for distant or near vision.

amplitude of a. the accommodative range of an eye.

histological a. changes in morphology and function of cells following changed conditions.

accreditation given a stamp of legitimacy and dependability by an authorized agency.

accredited recognition by an appropriate authority that the performance of a particular institution has satisfied a prestated set of criteria.

a. flocks chicken focks proven to be free of diseases designated by the National Poultry Improvement Plan.

a. herds cattle herds which have achieved a low level of reactors to, e.g. the tuberculin or brucellosis agglutination tests.

a. inspectors veterinarians who have attended appropriate continuing education courses and performed well enough through a probationary period to be accredited as part-time veterinary inspectors; employed by governments or more local authorities.

a. schools in some countries a governmental or professional body conducts periodic examinations of the country’s veterinary schools to determine their efficacy as teaching schools. Schools which lose their accreditation usually lose their status as providers of veterinary graduates who are adequate to the needs of the country’s animals. Accreditation assures prospective students that they will meet a competency threshold for entry into practice, including eligibility for professional credentialing and/ or licensure; faculty, deans and administrators that their programs measure satisfactorily against national standards and their own stated missions and goals; and employees that graduates have achieved specified learning goals and are prepared to begin professional practice. In North America, veterinary schools receive accreditation by the AVMA Council on education (COE) and institutions training veterinary technicians by the AVMA Committee on Veterinary Technician Education and Activities (CVTEA).

a. veterinarian one who is licensed to practice in a state and has passed a set of state/federal examinations to be accredited to act as an agent of the government and perform such activities as Bangs vaccination, examination of animals and subsequent issuing of health certificates for inter-state movement.

accretion [-kre’shn] 1. growth by addition of material. 2. accumulation. 3. adherence of parts normally separated.

accumulation points in acupuncture located on the meridian where the energy is greatest. Called also Xi-Cleft points.

accumulator plants plants which accumulate unusually large amounts of particular elements; includes facultative accumulators, e.g. Aster, Atriplex spp. which accumulate a particular element, e.g. selenium, but can grow quite well without it, and obligate accumulators which only grow in soils where high concentrations of the elements exist, e.g. Oonopsis, Xylorrhiza and some Astragalus spp.

accumulator plates battery components made of lead and a frequent cause of poisoning when chewed or licked.

accuracy [ak’u-r-se] 1. the closeness with which an observation or a measurement of a variable approximates its true value. An important component of diagnostic tests. An accurate test implies freedom from both random and systematic error. See also precision. 2. degree of conformance between the estimated or measured position of a GPS receiver and its true position. Differential positioning can be used to improve positioning accuracy by determining the positioning error at a known location by comparison to a known reference position.

ACD acid citrate dextrose; an anticoagulant solution used for the collection of blood for purposes of storage and transfusion. The active principle is sodium citrate with citric acid and dextrose.

ACE angiotensin-converting enzyme.

ACE inhibitors a group of drugs used as vasodilators in the management of heart failure. They act to decrease circulating concentrations of angiotensin II and aldosterone. See captopril, enalapril, lisinopril.

ace acepromazine.

acedapsone [as″ dap’sōn] a sulfone, related to dapsone, used in the treatment of leprosy in humans and atypical mycobacterial infections in animals.

acellular [a-sel’u-lr] not cellular in structure.

acelomate [a-se’l-māt] having no celom or body cavity.

acemannan [a-se man’an] a complex polysaccharide derived from the plant aloe barbadensis (aloe vera) and used as an immunostimulant.

acenocoumarol [-se″no-koo’m-rol] a warfarin derivative used as an anticoagulant. Called also nicoumalone.

acentric [a-sen’trik] 1. not central; not located in the center. 2. a chromatid or chromosome which lacks a centromere.

acephalobrachia [a-sef″-lo-bra’ke-] congenital absence of the head and forelimbs.

acephalocardia [a-sef″-lo-kahr’de-] congenital absence of the head and heart.

acephalocardius [a-sef″-lo-kahr’de-us] a fetus without a head or heart.

acephalochiria [a-sef″-lo-ki’re-] congenital absence of the head and forefeet.

acephalogastria [a-sef″-lo-gas’tre-] congenital absence of the head, thorax and stomach.

acephalopodia [a-sef″-lo-po’de-] congenital absence of the head and hindfeet.

acephalopodius [a-sef″-lo-po’de-us] a fetus without a head or hindfeet.

acephalorachia [a-sef″-lo-ra’ke-] congenital absence of the head and vertebral column.

acephalostomia [a-sef″-lo-sto’me-] congenital absence of the head, with the mouth aperture on the upper aspect of the body.

acephalothoracia [a-sef″-lo-tho-ra’se-] congenital absence of the head and thorax.

acephalous [a-sef’-ls] headless.

acephalus [a-sef’-ls] a headless fetus.

acepromazine [as″-pro’m-zēn] one of the phenothiazine derivative psychotropic drugs, used in animals as a means of chemical restraint. Its principal value is in quietening and calming frightened and aggressive animals. The standard pharmaceutical preparation, acepromazine maleate, is used extensively in horses, cats and dogs, especially as a preanesthetic agent. Called also acetylpromazine.

Acer [a’sr] trees of the family Aceraceae.

A. rubrum ingestion of wilted or dries leaves of this tree causes acute hemolytic anemia characterized by red urine, jaundice, anemia and methemoglobinemia in horses. Called also red maple, swamp maple.

acervuli calcified granules sometimes found in the pineal body and choroid plexus, especially in horses; structure similar to hydroxyapatite crystals; appear to have glial or stromal origin. Called also brain sand, corpora arenacea, psammoma bodies.

acervuline [-sur’vu-līn] aggregated; heaped up; said of certain glands.

acervulus [-sur’vu-ls] pl. acervuli [L.] sandy calcifications in or about the pineal body and choroid plexus.

acetabular [as″-tab’u-lr] pertaining to the acetabulum.

a. cup the acetabular component of a total artificial hip arthroplasty.

a. dysplasia see hip dysplasia.

a. plate an orthopedic plate designed specifically for repair or fixation of the acetabulum.

a. sourcil see sourcil.

acetabulectomy [as″-tab″u-lek’t-me] excision of the acetabulum.

acetabuloplasty [as″-tab’u-lo-plas″te] plastic repair of the acetabulum.

acetabulum [as″-tab’u-lm] the cup-shaped socket of the hip joint that receives the head of the femur. See also acetabular.

inherited a. defect in Dole horses; clinically normal at birth but with shallow acetabulum and flattened femoral head. Osteoarthritis and round ligament disruption develop later.

acetal [as’-tl] an organic compound formed by a combination of an aldehyde with an alcohol.

acetaldehyde [as″t-al’d-hīd″] a colorless volatile liquid, CH₃CHO, found in freshly distilled spirits, which is irritating to mucous membranes and has a general narcotic action. It is also an intermediate in the metabolism of alcohol.

acetaminophen [-se″t-min’-fen] an analgesic and antipyretic drug in dogs. It is contraindicated for cats because of serious sideeffects which include intravascular hemolysis, methemoglobinemia and hepatic necrosis. Called also paracetamol (INN).

acetanilide an analgesic and antipyretic. Like the other paraaminophenol derivatives, its toxicity is greater than that of salicylates and other analgesics so that it is not much used.

acetarsol, acetarsone [as″t-ahr’sol, as″t-ahr’sōn] an organic arsenical used as an antiprotozoal agent, especially in turkeys and geese. See also organic arsenic poisoning.

acetate [as’-tāt] a salt of acetic acid.

a. base cellulose acetate sheet used as support or base for X-ray film.

a. tape slide a method of collecting ectoparasites such as mites, lice or fleas, and their eggs, for diagnostic purposes by pressing the sticky side of the tape against the skin and haircoat and applying the tape to a glass slide which is then examined microscopically.

acetazolamide [as″et--zol’-mīd] a carbonic anhydrase inhibitor used to reduce aqueous humor production and thereby intraocular pressure in the treatment of glaucoma.

acetic [-se’tik] pertaining to vinegar or its acid; sour.

a. acid CH₃COOH, a short-chain, saturated fatty acid, the characteristic component of vinegar and one of the principal acids formed in the rumen by fermentation. It has the odor of vinegar and a sharp acid taste. A 36.5% solution of acetic acid is used topically as a caustic and rubefacient. A dilute acetic acid solution (6%) may be used as an antidote to alkali, e.g. in urea poisoning in cattle where the urea is converted to ammonia in the rumen. Glacial acetic acid is a 99.4% solution.

acetoacetate [-se″to-as’-tāt] see acetoacetic acid.

acetoacetic acid [-se″to--se’tik] CH₃COCH₂COOH, one of the ketone bodies formed in the body in metabolism of certain substances, particularly in the liver in the oxidation of fats, and utilized in extrahepatic tissues to obtain energy. It is present in the body in increased amounts in abnormal conditions such as uncontrolled diabetes mellitus and starvation, and in bovine ketosis and pregnancy toxemia of cows and ewes. Occurs in the body as acetoacetate.

acetoacetyl CoA [as″-to-as’-tl, -se’to-as--tēl″ko-a’] intermediate in ketogenesis and utilization of the ketones, β-hydroxybutyrate and acetoacetate. Penultimate intermediate in the beta-oxidation of fatty acids.

acetohexamide [as″-to-hek’s-mīd] a first generation sulfonylurea derivative, used as an oral hypoglycemic agent in the treatment of diabetes mellitus.

acetohydroxamic acid (AHA) [as″-to-hi″droks-am’ik] a hydroxamic acid that specifically inhibits urease; it retards alkalinization of the urine caused by urease-producing bacteria and may inhibit bacterial growth. Used in the prevention and dissolution of uroliths, but in dogs causes a dose-related, reversible hemolytic anemia and blood dyscrasia.

acetokinase [as″-to ki’nās] enzyme catalyzing the phosphorylation of acetate using ATP.

acetone [as’-tōn] a compound, CH₃COCH₃, with solvent properties and characteristic odor, obtained by fermentation or produced synthetically; it is a by-product of acetoacetic acid. Acetone is one of the ketone bodies produced in abnormal amounts in uncontrolled diabetes mellitus, metabolic acidosis, pregnancy toxemia and ketosis of ruminants. Unlike the other ketone bodies, acetone cannot be used by the tissues to generate energy and is excreted as a waste product in the urine and by exhalation. The characteristic fruity odor on the breath of animals with ketosis is due to the exhalation of acetone.

a. bodies acetone, acetoacetic acid and β-hydroxybutyric acid, being intermediates in fat metabolism. Called also ketone bodies.

a. poisoning in companion animals causes narcosis, gastritis and renal and hepatic damage.

acetonemia [as″-to-ne’me-] ketonemia; see ketosis.

acetonuria [as″-to-nu’re-] ketonuria.

acetophenazine a phenothiazine, similar to chlorpromazine, used as a tranquilizer.

acetophenetidin see phenacetin.

Acetosella vulgaris Rumex acetosella.

acetretin a synthetic derivative of vitamin A; a retinoid. Used in the treatment of primary seborrhea to normalize epithelial keratinization.

acetrizoate sodium [as″-tri-zo’āt] the sodium salt of acetrizoic acid, used as a contrast medium in radiography.

acetyl [as’-tl, as’-tēl″ -se’tl] the monovalent radical, CH₃CO, a combining form of acetic acid.

acetyl CoA [as’-tl, as″-tēl’ ko-a’] key intermediate in aerobic intermediary metabolism of carbohydrates, lipids and some amino acids. Carrier of acetyl groups into the tricarboxylic acid (Krebs) cycle and the chief precursor of lipids; it is formed by the attachment to coenzyme A of an acetyl group during the oxidation of pyruvate, fatty acids or amino acids. The only intermediate used up (ie not re-generated) in the Krebs cycle. Allosteric regulator of the activity of the pyruvate dehydrogenase complex and pyruvate carboxylase. Present in low concentrations but with high turnover. Dependent on B-group vitamin, pantothenic acid for structure of coenzyme A.

acetyl CoA carboxylase [as’-tl-, as″-tēl’ko-a’ kahr-bok’s-lās] a biotincontaining enzyme which participates in the synthesis of fatty acids by catalyzing the carboxylation reaction in which acetyl-CoA is converted to malonyl-CoA. It has the important effect of regulating the rate of fatty acid synthesis and is itself influenced in its activity by the local concentration of magnesium, citrate, palmitylcarnitine and ATP and is stimulated by the action of insulin.

acetylandromedol [as″-tl-, as″-tēl-an-drom’-dol] grayanotoxin (andromedotoxin).

acetylation [-set″-la’shn] one of the synthetic biotransformations which operate in the metabolism of drugs in which metabolites are produced that are more readily excreted than the parent drug. Dogs are exceptional amongst the domesticated species in that acetylation does not occur in their tissues. Acetylation is one of the principal metabolic pathways of the sulfonamides.

acetylator [-set″-la’tr] an organism capable of metabolic acetylation. Those animals that differ in their inherited ability to metabolize certain drugs, e.g. isoniazid, are termed fast or slow acetylators.

acetylcarnitine [as″-tl kahr’n-tēn] a substance which can act as a carrier for acetyl groups across the inner mitochondrial membrane in mammalian liver.

acetylcholine (ACh) [as″-tl-, as″-tēl-ko’lēn] the acetic acid ester of choline, normally present in many parts of the body and having important physiological functions. It is a neurotransmitter at cholinergic synapses in the central, sympathetic and parasympathetic nervous systems. It is not used clinically but it is the classical cholinergic agonist.

a. receptors structures located at the endorgans, e.g. at the skeletal muscle fibers. The myofibers are stimulated to contract by the interaction of acetylcholine with acetylcholine receptors which are located on the motor end plate or postsynaptic sarcolemma. See also neuromuscular junction. An immunologic test for acetylchoine receptors is used in the diagnosis of acquired myasthenia gravis.

acetylcholinesterase (AChE) [as″-tl-, as″-tēl-ko″l-nes’t-rās] an enzyme present in nervous tissue, muscle and red cells that catalyzes the hydrolysis of acetylcholine to choline and acetic acid; called also true cholinesterase.

a. antagonists organophosphorus compounds and carbamates that act by inactivating acetylcholinesterase; hence poisoning by these compounds has parasympatheticomimetic manifestations.

acetylcoenzyme A [as’-tl, as″-tēl’ ko-en’zīm] see acetyl CoA.

N-acetylcysteine [as″-tl-, as″-tēl-sis’te-ēn] a mucolytic agent used to reduce the viscosity of secretions of the respiratory tract. The principal method of administration is by aerosol, which in animals requires the use of a face mask or aerosol chamber. Also used parenterally in the treatment of acetaminophen poisoning in cats where it aids in detoxification of the drug and enhances its elimination, and topically in the treatment of collagenase-associated corneal ulcers.

acetylene [-set’-lēn] a colorless, combustible, explosive gas, the simplest triple-bonded hydrocarbon.

acetylethylenimine [as″-tl eth″l-en’-mēn] one of a group of related alkylating agents used in the preparation of inactivated vaccines.

N-acetylgalactosamine [as″-tl-, as″-tēl-gal″ak-tōs’-mēn] one of the repeating disaccharide units in glycosaminoglycans.

N-acetyl-glucosamine-6-sulfatase [as″-tl-, as″-tēl″gloo-kōs’-mēn sul’f-tās] an enzyme which when deficient in Nubian goats causes a condition similar to Sanfilippo’s III-D syndrome in humans; the clinical syndrome includes delay in rising and walking in neonates, ataxia, bowing of front limbs, clouding of the cornea, dwarfism, and cartilaginous and bony deformities; histological examination reveals lysosomal overload.

N-acetylglutamate [as″-tl-, as″-tēl-gloo’t-māt] compound produced from acetyl CoA and glutamate that provides the regulator stimulus to the activity of carbamoyl synthetase II of the urea cycle.

N-acetyl loline alkaloid a compound thought to contribute to fescue poisoning.

acetyl-β-methylcholine see methacholine.

acetylpromazine [-se’tl pro’m-zēn] acepromazine.

acetylsalicylic acid [-se’tl-sal″-sil’ik] see aspirin.

acetylstrophanthidin [as″-tl-, as″-tēl″stro-fan’th-din] a semisynthetic cardiac glycoside, similar to strophanthin.

AcG accelerator globulin (clotting factor V).

ACh acetylcholine.

acha see Digitaria exilis.

achalasia [ak″-la’zh] failure to relax of the smooth muscle fibers of the gastrointestinal tract at any junction of one part with another; especially failure of the lower esophagus to relax with swallowing, due to an abnormality of innervation. Called also cardiospasm. See also megaesophagus.

cricoesophageal a. failure of the cranial esophageal sphincter to relax during swallowing to accommodate the approaching bolus. Gagging, nasal regurgitation and aspiration result. Called also cricoesophageal incoordination.

cricopharyngeal a. is motor dysfunction of the cricopharyngeal sphincter in which a failure of relaxation prevents the bolus from entering the esophagus during swallowing. Called also cricopharyngeal dysphagia.

esophageal a. see megaesophagus.

pyloric a. failure of the pylorus to open in neonates so that distention of the stomach occurs and causes continuous vomiting. This may be reflex in response to local ulceration, e.g. in young calves, or be a congenital defect.

reticulo-omasal sphincter a. is probably a factor in the development of the gut stasis in bovine vagal indigestion with onward passage of ingesta obstructed at the exit from the rumenoreticulum. Results in rumen distention and frothiness of contents.

AChE acetylcholinesterase.

ache [āk] 1. continuous pain, as opposed to sharp pangs or twinges. An ache can be either dull and constant, as in some types of backache, or throbbing, as in some types of headache and toothache. An ache is a subjective sensation and its occurrence in animals is only assumed. 2. to suffer such pain.

acheilia [-ki’le-] a developmental anomaly with absence of the lips.

acheiria [-ki’re-] a developmental anomaly with absence of the forefeet.

acheiropodia [-ki″ro-po’de-] a developmental anomaly characterized by absence of all feet, both fore and hind.

Achilles tendon [-kil’ēz] the group of tendons that insert on the calcaneus near the point of the hock made up of the tendons of the gastrocnemius, soleus, superficial digital flexor, semitendinosus and biceps femoris muscles. Called also common calcaneal tendon. See also gastrocnemius muscle tendon.

achillobursitis [-kil″o-br-si’tis] inflammation of the bursae about the gastrocnemius tendon.

achillodynia [-kil″o-din’e-] pain in the Achilles tendon or its bursa.

achillorrhaphy [ak″-lor’-fe] suturing of the gastrocnemius tendon.

achillotenotomy [-kil″o-t-not’-me] surgical division of the gastrocnemius tendon.

achlorhydria [a″klor-hi’dre-] absence of hydrochloric acid from gastric juice.

Achly [ak’le-] fungus which causes white, cotton-wool like growths on cutaneous trauma sites of fish and their newly spawned eggs; most common at colder water temperatures.

Achnatherum spp. see Stipa.

Acholeplasma [a″ko-le-plaz’m] a genus of the class Mollicutes and related to the genus Mycoplasma.

A. laidlawii a common isolate from the lungs of calves with enzootic pneumonia but of doubtful significance.

A. oculi is a common finding in the conjunctivae of sheep with contagious ophthalmia but not proven to be pathogenic in this situation.

acholia [a-ko’le-] lack or absence of bile secretion.

acholic feces [a-ko’lik] gray, putty-colored feces resulting from an absence of oxidized bile pigments in the intestinal tract; usually indicative of complete bile duct obstruction, but pale color can also be caused by dietary factors or reduced bacterial activity in the intestine, e.g. decreased transit time, or by antibacterial therapy.

acholuria absence of bile pigments from the urine.

achondrogenesis [a-kon″dro-jen’-sis] a hereditary disorder characterized by hypoplasia of bone, resulting in markedly shortened limbs; the head and trunk are normal.

achondroplasia [a-kon″dro-pla’zh] a failure of growth of cartilage in the young, leading to a type of short-legged dwarfism. Several breeds of dogs display this in their standard conformation, e.g. Dachshund, Basset hound, Corgi. In dogs of this stature, this has been related to an extra copy of the gene that codes for a growth-promoting protein, called fibroblast growth factor 4 (FGF-4). See also chondrodysplasia.

inherited congenital a. see achondroplastic dwarfism.

inherited a. dwarfism see achondroplastic dwarfism.

inherited a. with hydrocephalus see bulldog calves.

AChR acetylcholine receptor.

Achorion see Trichophyton.

achromasia [ak″ro-ma’zh] 1. lack of normal skin pigmentation. 2. the inability of tissues or cells to be stained.

achromat [ak’ro-mat] an achromatic microscope objective.

achromatic [ak″ro-mat’ik] 1. producing no discoloration, or staining with difficulty. 2. refracting light without decomposing it into its component colors.

achromatism [-kro’m-tiz-m] the quality or the condition of being achromatic; staining with difficulty.

achromatophil [ak″ro-mat’o-fil] 1. not easily stainable. 2. an organism or tissue that does not stain easily.

achromatosis [-kro″m-to’sis] 1. deficiency of pigmentation in the tissues. 2. lack of staining power in a cell or tissue.

achromatous [-kro’m-tus] colorless.

achromaturia [-kro″m-tu’re-] colorless state of the urine.

achromia [-kro’me-] the lack or absence of normal color or pigmentation, as of the skin.

achromocyte [-kro’mo-sīt] a red cell artifact that stains more faintly than intact red cells.

achromoderma amelanosis; lack of pigment in the skin.

achromophil [-kro’mo-fil] see achromatophil.

achromotrichia [a-kro″mo-trik’e-] loss or absence of pigment in hair. It may be complete or patchy, affect the length of the fiber or be in well-defined bands or speckled. Can be caused by nutritional deficiency, selective freezing, radiation or pressure. See also vitiligo, copper nutritional deficiency.

Achtheres a genus of the class Crustacea which parasitize freshwater fish.

Achyla a genus of fungi which cause disease in fish reared by fish culturists and aquarists.

achylia [-ki’le-] absence of hydrochloric acid and enzymes in the gastric secretions.

achylous deficient in chyle.

achymia [-ki’me-] deficiency of chyme.

acicular [-sik’u-lr] acicularis [L.]; needle-shaped.

acid [as’id] 1. sour. 2. a molecule or ion with a tendency to give up a proton to the solvent according to Bronsted and Lowry theory. All acids react with bases to form salts and water (neutralization). Other properties of acids include a sour taste and the ability to cause certain dyes to undergo a color change. A common example of this is the ability of acids to change litmus paper from blue to red. Acids play a vital role in the chemical processes that are a normal part of the functions of the cells and tissues of the body. A stable balance between acids and bases in the body is essential to life. See also acidic, acid–base balance, and individual acids.

amino a. any one of a class of organic compounds containing the amino and the carboxyl group, occurring naturally in plant and animal tissues and forming the chief constituents of protein. See also amino acid.

bile a’s steroid acids derived from cholesterol. See also bile acids.

chlorinated a’s. some, e.g. trichlorbenzoic acid, sodium chloroacetate, sodium trichloroacetate, are used as weedkillers and are relatively harmless as far as animals are concerned.

a. excretion blood buffers prevent a sudden change in pH of body fluids when they receive excess acid or alkali from absorption or metabolic processes. This temporary measure is supplemented by a mechanism for the excretion of hydrogen ions via the kidney in the form of dihydrogen phosphate and ammonium ions.

fatty a. any monobasic aliphatic acid containing only carbon, hydrogen and oxygen. See also fatty acid.

a. hydrolases major group of enzymes present in lysosomes.

inorganic a. an acid containing no carbon atoms.

keto a’s compounds containing the groups CO (carbonyl) and COOH (carboxyl).

a. methyl green stain stains protozoal nuclei a bright green and is recommended for the detection of Balantidium coli in fecal smears.

net a. excretion (NAE) the measurement of urinary NAE to provide a method for evaluating acid-base balance in companion animals. Based on the fact that the kidneys play a central role in acid-base homeostasis by adjusting urine electrolyte excretion to maintain constant blood pH. Measurement of net base excretion (NBE) is more appropriate in cattle and other herbivores because urine pH is usually alkaline. NBE=-NAE, with both being measured in milliequivalents per liter.

nucleic a’s macromolecules containing phosphoric acid, sugars, and purine and pyrimidine bases that carry genetic information. Deoxyribose nucleic acid (DNA) and ribose nucleic acid (RNA) are the most common nucleic acids. See also nucleic acids.

a. phosphatase see acid phosphatase.

a. retention retention of metabolic acids, including sulfates and phosphates, as a result of acute and chronic renal disease.

acid–antigen plate test [as’id an’t-jn plāt] see rose bengal test.

acid–base balance [as’id-bās bal’ns] a state of equilibrium between acidity and alkalinity of the body fluids; called also hydrogen ion (H+) balance because, by definition, an acid is a substance capable of giving up a hydrogen ion during a chemical exchange, and a base is a substance that can accept it. The positively charged hydrogen ion (H+) is the active constituent of all acids. Most of the body’s metabolic processes produce acids as their end products, but a somewhat alkaline body fluid (pH 7.4) is required as a medium for vital cellular activities. Therefore chemical exchanges of hydrogen ions must take place continuously in order to maintain a state of equilibrium. An optimal pH (hydrogen ion concentration) between 7.35 and 7.45 must be maintained; otherwise, the enzyme systems and other biochemical and metabolic activities will not function normally. Although the body can tolerate and compensate for slight deviations in acidity and alkalinity, if the pH drops below 7.30, the potentially serious condition of acidosis exists. If the pH goes higher than 7.50, the patient is in a state of alkalosis. In either case the disturbance of the acid–base balance is considered serious, even though there are control mechanisms by which the body can compensate for an upward or downward change in the pH. Shifts in the pH of body fluids are controlled by three major regulatory systems which may be classified as chemical (the buffer systems), biological (blood and cellular activity), and physiological (the lungs and kidneys). The Henderson-Hasselbalch equation is used to categorize four primary acidbase disturbances: respiratory acidosis (increased PCO₂), respiratory alkalosis (decreased PCO₂), metabolic acidosis (decreased extracellular base excess), or metabolic alkalosis (increased extracellular base excess). The anion gap is calculated to detect the presence of unidentified anions in plasma. This approach works well with clinical problems when serum total protein, albumin, and phosphate concentrations are approximately normal. The strong-ion difference method of evaluating acid-base balance, based on the concept that pH is primarily determined by PCO₂, strong ion difference (SID), and nonvolatile buffer concentration (ATOT) and categorizes acid-base disturbances into six categories: respiratory acidosis and alkalosis, strong ion acidosis and alkalosis, nonvolatile buffer ion acidosis and alkalosis. It is recommended for use whenever serum total protein, albumin, and phosphate concentrations are markedly abnormal and where lactate, ketoacids, and uremic anions are contributory to the acid-base disturbance.

acid citrate dextrose [as’id sit’rāt dek’strōs] see ACD.

acid-detergent fiber [as’id de-tur’jnt fi’br] see acid-detergent fiber².

acid etch technique [as’id ech tek-nēk’ ] the use of dilute acid, commonly phosphoric acid, on teeth to improve their ability to retain restorative materials.

acid-fast [as’id-fast] 1. not readily decolorized by acids after staining; said of bacteria, especially Mycobacterium spp. 2. stain demonstrating this characteristic. See also Ziehl-Neelsen stain.

modified a.-f. bacteria resist decolorization by mild acid solutions; includes Brucella and Nocardia.

acidification a technology used by processors to preserve foods by adding acids (such as acetic, citric, phosphoric, propionic and lactic acid) and thereby reduce the risk of growth of harmful bacteria. Also used to preserve colostrum and milk for feeding calves.

a. of feed used to enhance the stomach acidity, reducing pH and salmonella infection as well as improving pig performance.

acid phosphatase [as’id fos’f-tās] a lysosomal enzyme that hydrolyzes phosphate esters liberating phosphate, showing optimal activity at a pH between 3 and 6; found in erythrocytes, prostatic tissue, spleen, kidney and other tissues.

acid-proof acid-fast.

acid rain rain which contains materials, sulfates and oxidation products of nitrogen and sulfur particularly, produced by combustion of coal and oil in industrial processes and by motor vehicles; lowers the pH of water bodies; see acid waters; credited with local decline of fish culture.

acid waters waters with a low pH occurring naturally and where water contaminated by acid rain and run-off from mine sites; acid waters often contain higher concentrations than normal of cadmium, copper, zinc and lead. Water affected by heavy leaching from soil may contain high concentrations of aluminum, copper, manganese and iron. These waters adversely affect production in fish cultures. See also water acidity.

acidaminuria aminoaciduria.

acidemia [as″-de’me-] abnormal acidity of the blood.

acidic [-sid’ik] of or pertaining to an acid; acid-forming.

a. urine is usual in carnivores, that of herbivores is usually neutral or slightly alkaline. Urine increases in acidity when a large load of acid is passed into the extracellular fluid and is excreted by the kidneys. If the kidneys can cope with the excretion load the pH of the blood will return to normal. If the acid load is too great or the kidney function inadequate, acidemia results.

acidified milk replacer liquid milk substitute acidified to pH 5.2 to preserve it and to reduce the intake so that the calf takes more frequent but smaller meals during the day.

acidifier [-sid″-fi’r] an agent that causes acidity; a substance used to increase gastric or urine acidity.

acidifying solution a solution used in fluid therapy for alkalosis.

acidity [-sid’-te] 1. the quality of being acid; the power to unite with positively charged ions or with basic substances. 2. excess acid quality, as of the gastric juice.

gastric a. is maintained by the secretion of hydrochloric acid by the oxyntic or parietal cells located in the mucosa of stomach or abomasum.

water a. fish can tolerate only a narrow range of pH in the water in which they swim. Naturally occurring acidification, such as occurs in waters draining from acid soils, can cause fish deaths.

acidophil [-sid’o-fil″] 1. a histological structure, cell, or other element staining readily with acid dyes. 2. two types of cells in the pars distalis of the pituitary gland that secrete somatotropin and luteotropin. 3. an organism that grows well in highly acid media. 4. acidophilic.

a. neoplasms adenomas and adenocarcinomas of the pars distalis of the pituitary gland are recorded in cats, dogs, sheep and rats. These are infrequently functional but may have space-occupying effects on the pituitary and hypothalamus. They have been associated with diabetes mellitus in cats, galactorrhea in ewes, and metahypophyseal diabetes in dogs.

acidophile [-sid’o-fīl″] see acidophil.

acidophilic [as″-do-fil’ik] 1. easily stained with acid dyes. 2. growing best on acid media.

hepatocellular a. bodies see cytosegresome formation.

acidosis [as″-do’sis] a pathological condition resulting from accumulation of acid or depletion of the alkaline reserve (bicarbonate content) in the blood and body tissues, and characterized by increase in hydrogen ion concentration (decrease in pH). The optimal acid–base balance is maintained by chemical buffers, biological activities of the cells, and effective functioning of the lungs and kidneys. The opposite of acidosis is alkalosis. It is rare that acidosis occurs in the absence of some underlying disease process. The more obvious signs of severe acidosis are muscle twitching, involuntary movement, cardiac arrhythmias, disorientation and coma.

compensated a. condition in which the compensatory mechanisms have returned the pH toward normal.

diabetic a. a metabolic acidosis produced by accumulation of ketones in uncontrolled diabetes mellitus.

hypercapnic a. respiratory acidosis.

iatrogenic a. may result from administration of drugs, such as urinary acidifiers, or anesthetic agents which depress respiration.

lactic a. a form of metabolic acidosis associated with accumulation of lactic acid, resulting fromtissue hypoperfusion and hypoxia leading to anaerobic glycolysis or, rarely, errors of metabolism. Reptiles are particularly susceptible to lactic acidosis. The accumulation of lactate in the rumen in ruminants and the stomach of horses, and hence in the blood, occurs as a result of overfeeding with readily fermentable carbohydrate. See also carbohydrate engorgement.

metabolic a. acidosis resulting from accumulation in the blood of keto acids (derived from fat metabolism) at the expense of bicarbonate, thus diminishing the body’s ability to neutralize acids. This type of acidosis can occur when there is an acid gain, as in diabetic ketoacidosis, lactic acidosis, poisoning and failure of the renal tubules to reabsorb bicarbonate. It can also result from bicarbonate loss due to diarrhea or a gastrointestinal fistula.

mixed alkalosis and a. characterized by low serum chloride, normal or slightly elevated plasma bicarbonate and a very high anion gap.

nonrespiratory a. results from loss of bicarbonate from the extracellular fluid, e.g. in diarrhea and paralytic ileus. Called also metabolic acidosis.

organic a. accumulation of organic anions occurs in uremia, diabetic acidosis and lactic acidosis, and ingestion of salicylates, ethylene glycol or methanol.

renal tubular a. renal tubular malfunction leads to faulty resorption of bicarbonate or excretion of acid and the production of alkaline urine; types I (distal tubular acidosis) and II (proximal tubular acidosis) are identified.

respiratory a. acidosis resulting from ventilatory impairment and subsequent retention of carbon dioxide.

ruminal a. acidosis caused by an altered metabolic state, usually lactic acidosis, in the rumen.

starvation a. a metabolic acidosis due to accumulation of ketones following a severe caloric deficit.

uncompensated a. a condition in which the compensatory mechanisms have not been applied sufficiently to return the pH of the blood to normal.

uremic a. see metabolic acidosis (above).

acidum [L.] acid.

aciduria [as″-du’re-] the excretion of acid in the urine. See also specific forms, such as aminoaciduria, orotic aciduria (below).

orotic a. appearance of orotic acid, an intermediate of pyrimidine synthesis, in the urine due to a lack of orotate phosphoribosyltransferase activity.

paradoxical a. occurs when a metabolic alkalosis caused by severe vomiting or pooling of gastric secretions in the abomasum leads to renal bicarbonate reabsorption and sodium–hydrogen exchange with the inappropriate production of acid urine.

aciduric [as″-doo’rik] capable of growing well in extremely acid media.

acinar [as’-nr] pertaining to or affecting an acinus or acini.

acinetic [as″-net’ik] akinetic.

Acinetobacter [as″-net″o-bak’tr] gram-negative bacteria commonly found in the environment and often normal flora in animals and humans, but have been associated with nosocomial and opportunistic infections in a range of species with bronchopneumonia in mink and occasionally seen as a cause of bovine mastitis.

aciniform [-sin’-form] grapelike.

acinitis [as″-ni’tis] inflammation of the acini of a gland.

acinitrazole used as a treatment and prophylactic for blackhead in turkeys; low toxicity but excessive dosing causes infertility and liver and kidney damage.

acinonodular aciniform.

acinous [as’-ns] made up of acini.

acinus [as’-ns] pl. acini [L.] a small sac-like dilation; any of the smallest lobules of a compound gland.

hepatocellular a., hepatic a. an alternative concept of liver microstructure to that of the lobule. The hepatic acinus has as its center the portal triad whch is surrounded by an ovoid mass of hepatocytes, the most peripheral of which constitute the periacinar parenchyma. Between these masses and draining them are the hepatic venules (known as central veins by adherents to the lobular concept of liver structure).

liver a., hepatic a. the smallest functional unit of the liver made up of two wedge-shaped masses of liver parenchyma that are supplied by two neighboring, terminal branches of the portal vein and hepatic artery and drained by two central veins and by terminal branches of the bile duct.

acitretin [as″e-tret’in] an active metabolite of etretinate, with similar actions, but less toxic and with a shorter half-life; used in dermatology for the treatment of keratinization disorders.

ACLAM American College of Laboratory Animal Medicine.

aclasia, aclasis [-kla’zh, ak’l-sis] pathological continuity of structure, as in chondrodystrophy.

acme [ak’me] the critical stage or crisis of a disease.

acne [ak’ne] a disorder of the skin characterized by comedones that arise from papules and pustules. Secondary bacterial infection of hair follicles often occurs.

canine a. a skin disease of young, shorthaired dogs affecting the chin and lips. There are papules, which may be sterile, and later suppurative folliculitis and furunculosis. See chin pyoderma.

contagious equine a. see Canadian horsepox.

feline a. occurs in cats of any age, involving the skin on the point of the chin and the lips. There are crusts and comedones, which in severe cases may progress to suppurative folliculitis, furuncolosis and cellulitis. Although often idiopathic, Malassezia, dermatophytes and Demodex may be agents in some cases.

interdigital a. see interdigital pyoderma.

acneiform [ak’ne-form] resembling acne.

Acokanthera [ak″o-kan-the’r] a genus of the plant family Apocynaceae used in Africa in the preparation of arrow poisons. Poisoned livestock show diarrhea, irregular heartbeat and sudden death. Contain cardiac glycosides. Includes A. longiflora, A. oblongifolia, A. oppositifolia, A. schimperi, A. spectabilis (A. oblongifolia), A. venenata (A. oppositifolia). Some species were formerly classified in Carissa spp.

acokantherosis the state of being poisoned by Acokanthera spp.

Acomatacarus a trombidiform mite of the family Trombiculidae. The larvae are parasitic. Called also chiggers, scrub itch-mite. Includes A. australiensis (humans, dogs) and A. galli (chickens, mice, rats, rabbits).

Acomys cahirinus see spiny mouse.

aconite [ak’-nīt] see Aconitum.

aconitine [-kon’-tin] a mixture of alkaloids in Aconitum napellus. Causes abdominal pain, dyspnea, vomiting, diarrhea, cardiac irregularity.

Aconitum [ak″-ni’tm] a genus of the Ranunculaceae family from northern temperate areas. Includes A. brachypodium, A. carmichaelii, A. chasmanthum, A. columbianum, A. ferox, A. lycoctonum, A. vaccarum, A. vulpari.

A. napellus one of the most poisonous of European plants; cultivated in gardens. All parts of the plant contain aconitine, one of the plant’s toxic alkaloids. The dried tuberous root was used pharmaceutically as a counterirritant and local anesthetic. The plant is not usually eaten and field poisoning with it is uncommon. Signs of poisoning include vomiting, colic, slow heart rate, paralysis, pupillary dilatation and death due to asphyxia. Called also monkshood, wolf’s bane, aconite.

acoprosis absence or paucity of feces in the intestines.

A-9 Feline acne.

From Kummel BA, Color Atlas of Small Animal Dermatology. Mosby, 1989

< div class='tao-gold-member'>

Only gold members can continue reading. Log In or Register to continue

Related

Stay updated, free articles. Join our Telegram channel

Tags: Saunders Comprehensive Veterinary Dictionary

Jul 18, 2016 | Posted by admin in PHARMACOLOGY, TOXICOLOGY & THERAPEUTICS | Comments Off

Full access? Get Clinical Tree

Get Clinical Tree app for offline access

Get Clinical Tree app for offline access