P

P

P chemical symbol, phosphorus; symbol, peta-; position; presbyopia; [L.] proximum (near); pulse; [L.] punctum (point); pupil.

P₁ parental generation.

P1,P2,P3 phalanges, numbered from proximal to distal. In horses, called also long pastern (os compedale), short pastern (os coronale) and coffin (os ungulare) bones.

P₂ pulmonic second sound. See heart sounds.

p53 a tumor suppressor gene active in the cellular response to DNA damage and cell cycle arrest.

Pco² carbon dioxide partial pressure or tension; also written PCO₂, pCO₂ and pCO₂. See respiration and blood gas analysis.

Po₂ oxygen partial pressure (tension); also written PO₂, pO₂ and pO₂. See also blood gas analysis.

p symbol for (1) the short arm of a chromosome; or (2) the frequency of the more common allele of a pair; (3) pico-.

p- symbol, para-.

π pi, small letter; sixteenth letter in the Greek alphabet.

φ phi, small letter; twenty-first letter in the Greek alphabet.

ψ psi, small letter; twenty-third letter in the Greek alphabet.

P-450 enzymes superfamily of heme-containing monooxygenase enzymes important for detoxification of drugs, including pesticides, and the biosynthesis of steroid hormones from cholesterol; at high concentrations in some fish-eating birds, e.g. Atlantic puffins.

p-cresol see cresols.

P-K reaction Prausnitz-Küstner reaction.

P mitrale an electrocardiographic abnormality in which the P wave is prolonged, in dogs more than 0.04 s. Associated with left atrial enlargement.

P pulmonale an electrocardiographic abnormality in which the P wave is tall and peaked. Indicative of right atrial enlargement which is often associated with chronic pulmonary disease.

P site see peptidyl-tRNA binding site (under tRNA).

Pa chemical symbol, protactinium; symbol, pascal.

P_aCO₂ symbol for partial pressure of carbon dioxide in the arterial blood. See also blood gas analysis.

P_aO₂ symbol for partial pressure of oxygen in arterial blood. See also blood gas analysis.

PA inhibitor plasminogen activator inhibitor.

Paatsama technique a surgical method for reconstruction of a ruptured cranial cruciate ligament using a strip of fascia lata.

PAB, PABA para-aminobenzoic acid.

pabulum food or nourishment.

PAC Political Action Committee.

paca [pă′k] a large, plump rodent, brown in color, with three to five lines of white spots down the sides of the body. Called also sooty paca, spotted cavy, Cuniculus paca (formerly Coelogenys spp.).

pacchionian granulations [pak″e-o′ne-n] enlargements of the arachnoid villi which protrude into the dorsal sagittal sinus, as seen well developed in the horse.

pace an equine gait similar to a trot except that the front and rear limbs on each side are moved in unison instead of the diagonal limbs. A comfortable even gait for the rider, producing an even speed for the duration of a race. Similar to the amble gait but at a fast speed. Many pacing horses are raced and trained in harness. Called also sidewheel.

flying p. a natural gait of Icelandic horses.

pacemaker [pāsma-kr] 1. an object or substance that controls the rate at which a certain phenomenon occurs; often used alone to indicate an artificial cardiac pacemaker; however, there are other natural and artificial pacemakers. 2. In biochemistry, a pacemaker is a substance whose rate of reaction sets the pace for a series of interrelated reactions.

asynchronous p. (1) an implanted cardiac pacemaker in which the induced ventricular rhythm is independent of the atrium; it is usually set at a fixed rate of ventricular stimulation.

p. cells (1) cells within the heart capable of spontaneous discharge.

gastric p. (1) a saddle-shaped area of the greater curvature of the stomach at the junction of its proximal and middle thirds, which regulates the frequency of gastric contractions.

phrenic p. (1) a device designed to facilitate respiration by converting radiofrequency signals into electrical impulses that stimulate the phrenic nerve, resulting in contraction and flattening of the diaphragm and improved inspiration of air.

p. therapy implantation of a pacemaker device in animals usually for the treatment of symptomatic bradyarrhythmias.

p. syndrome falling arterial pressure, low cardiac output and congestive heart failure, usually due to a suboptimal pacing mode.

uterine p. either of the two regulating centers that control uterine contractions.

wandering p. a condition in which the site of origin of the impulses controlling the heart rate shifts from the head of the sinoatrial node to a lower part of the node or to another part of the atrium. Normal in the dog and horse.

Pacheco’s disease [p-chek′ōz] a disease of psittacines caused by a psittacid herpesvirus 1 and characterized by weakness, diarrhea and focal necrosis in the liver and spleen. Intranuclear inclusion bodies in hepatocytes suggest the diagnosis. The disease causes very heavy mortalities.

pachy- word element. [Gr.] thick.

pachyacria [pak″e-ak′re-] enlargement of the soft parts of the extremities.

pachyblepharon [pak″e-blef′-ron] thickening of the eyelids.

pachycephaly [pak″e-sef′-le] abnormal thickness of the bones of the skull.

pachycheilia [pak″e-ki′le-] thickening of the lips.

pachychromatic [pak″e-kro-mat′ik] having the chromatin in thick strands.

pachycurares [pak″e-koo-rah′rez] a group of neuromuscular blocking agents characterized by large, bulky molecules. Includes d-tubocurarine, gallamine, pancuronium; all of them are competitive blockers.

pachydactyly [pak″e-dak′t-le] megalodactyly.

pachyderma [pak″e-dur′m] abnormal thickening of the skin.

p. vesicae thickening of the mucous membrane of the bladder.

pachydermatocele [pak″e-dr-mat′o-sēl] plexiform neuroma attaining large size, producing an elephantiasis-like condition.

pachyglossia [pak″e-glo′se-] abnormal thickness of the tongue.

pachygyria [pak″e-ji′re-] see macrogyria.

pachyhematous [pak″e-dur′m-ts] pertaining to or having thickened blood.

pachyleptomeningitis [pak″e-lep″to-men″in-ji′tis] inflammation of all three meningeal layers.

pachymeninges [pak″e-m-nin′jēz] dura mater.

pachymeningitis [pak″e-men″in-ji′tis] inflammation of the dura mater; perimeningitis.

ossifying p. see dural ossification.

pachymeningopathy [pak″e-men″in-gop′-the] noninflammatory disease of the dura mater.

pachymeninx [pak″e-me′ninks] the dura mater.

pachynsis [p-kin′sis] an abnormal thickening.

pachyonychia [pak″e-o-nik′e-] abnormal thickening of the nails or claws.

pachyperiostitis [pak″e-per″e-os-ti′tis] periostitis of long bones resulting in abnormal thickness of affected bones.

pachyperitonitis [pak″e-per″-to-ni′tis] inflammation and thickening of the peritoneum.

pachypleuritis [pak″e-pl -ri′tis] fibrothorax.

pachysalpingitis [pak″e-sal″pin-ji′tis] chronic interstitial inflammation of the muscular coat of the oviduct producing thickening; called also mural salpingitis and parenchymatous salpingitis.

pachysalpingo-ovaritis [pak″e-sal-ping″go-o″v-ri′tis] chronic inflammation of the ovary and oviduct, with thickening.

pachysomia [pak″e-so′me-] thickening of parts of the body.

Pachystigma a genus of South African plants in the family Rubiaceae; the causative toxin is the polyamine toxin, pavetamine, which causes myocarditis and sudden death (gousiekte). Includes P. latifolium, P. pygmaeum, P. thamnus. Called also Vangueira spp., goubos, gousiektebossie.

pachytene [pak′e-tēn] in prophase of meiosis, the stage following zygotene during which the chromosomes shorten, thicken and separate into two sister chromatids joined at their centromeres. Paired homologous chromosomes, which were joined by synapsis, now form a tetrad of four chromatids. Where crossing over has occurred between nonsister chromatids, they are joined by Y-shaped chiasmata.

pachyvaginalitis [pak″e-vaj″-nl-i′tis] inflammation and thickening of the tunica vaginalis of the testis.

pachyvaginitis [pak″e-vaj″-ni′tis] chronic vaginitis with thickening of the vaginal walls.

Pacifastacus leniusculus American crayfish; signal crayfish.

Pacific Coast tick see Dermacentor occidentalis.

Pacific labrador tea Ledum columbianum.

pacing [pās′ing] 1. normal gait of some horses. See pace. 2. stereotyped pacing; a habit in all caged animals, especially if they are active species and are confined in very small areas. May cause excessive wear in footpads, in snakes the damage is usually to the front of the head. 3. setting the pace or rate of movement. See cardiac pacing.

pacinian corpuscle [p-sin′e-n] cutaneous mechanoreceptors that sense pressure and stretch.

pack [pak] 1. see sterile surgical pack. 2. jute container (13.5 cm × 7.5 cm × 7.5 cm) into which wool is packed to make a bale; other similar containers in which wool is packed include butts and sacks. 3. social unit that hunts, rears its young and protects a communal territory as a group.

packalacca Phytolacca dioica.

packed cell volume (PCV) the percentage of the volume of whole, unclotted blood occupied by the erythrocytes. A useful prognostic indicator in dehydration when the PCV rises markedly.

packer 1. an instrument for introducing a dressing into a cavity or a wound. 2. proprietor of a meat packing plant.

Packera see Senecio.

packet knot slip knot; useful for the beginning of a continuous suture.

packing [pak′ing] 1. the filling of a wound or cavity with gauze, sponge or other material. 2. the material used for this purpose.

packing plant [pak′ing] a complete meat production unit including facilities for slaughtering animals, processing of meat and offal, boning out, making up of blocks of carcasses, chilling, freezing, storing of the meat, preparation of by-products.

paclitaxel [pak″l-tak′sl] a cell cycle-specific antineoplastic drug; adverse reactions in dogs and cats to the vehicle, Cremophor EL, require careful pretreatment with antihistamines and corticosteroids. Known as TaxolW.

PACS Picture Archiving and Communication System; a computer system of hardware and programs for the storage, display, transfer, archival and communication system of radiographic and other diagnostic images.

pad [pad] a cushion-like mass of soft material which may be (1) anatomical; (2) surgical.

abdominal p. a pad for the absorption of discharges from abdominal wounds, or for packing off abdominal viscera to improve exposure during surgery.

communal p. metacarpal pad.

fat p. a pad of fat lying within a joint, covered with synovial membrane and thought to assist in the spreading of synovial lubricant, e.g. infrapatellar fat pad of stifle joint.

foot p’s see footpad.

Mikulicz’s p. a pad made of folded gauze, for packing off viscera in surgical procedures.

pressure p. in surgery, gauze sponges used to apply pressure in the control of minor hemorrhage.

stripped p. avulsion of the pad with exposure of the dermis. A common injury in Greyhounds which have raced on asphalt or been over-exercised on a walking machine with a rough belt.

pad-saddle a thick pad of felt made like a saddle but without a tree. Can be made in leather with a minor arch. Used for riding horses in track work.

Padda oryzivora see Java sparrow.

paddock a fenced field or enclosure.

joining p. used for mating.

PAE post-antibiotic effect.

Paecilomyces a genus of soil-inhabiting imperfect fungi which are sometimes found as contaminants of the skin and oral mucosa. See also hyalohyphomycosis.

P. fumosoroseus associated with cutaneous and disseminated infections in dogs and cats.

P. varioti an opportunistic fungal infection of the respiratory tract of birds.

Paenibacillus larvae subspecies larvae the cause of American foulbrood in honeybees. Previously classified as Bacillus larvae.

PAF platelet activating factor.

Pagrus auratus finfish in family Sparidae. Called also snapper, red sea bream.

-pagus word element. [Gr.] conjoined twins.

PAH, PAHA para-aminohippuric acid.

Pahvant Valley fever see tularemia.

pail-fed said of neonates reared on milk or replacer fed from a pail instead of a bottle. Called also bucket-fed.

pail-feeding a method of rearing calves by weaning them off the dam and feeding them on her or another cow’s milk or milk replacer in a bucket without the use of a nipple. Because of the common practice of feeding at too long intervals with cold milk there is a higher prevalence of dietary diarrhea in pailfed calves than in calves that are suckled. See also dietary diarrhea.

pain [pān] a feeling of distress, suffering or agony, caused by stimulation of specialized nerve endings. Its purpose is chiefly protective; it acts as a warning that tissues are being damaged and induces the sufferer to remove or withdraw from the source. All receptors for pain stimuli are free nerve endings of groups of myelinated or unmyelinated neural fibers abundantly distributed in the superficial layers of the skin and in certain deeper tissues such as the periosteum, surfaces of the joints, arterial walls, and the falx and tentorium of the cranial cavity. The distribution of pain receptors in the gastrointestinal mucosa apparently is similar to that in the skin; thus, the mucosa is quite sensitive to irritation and other painful stimuli. Although the parenchyma of the liver and the alveoli of the lungs are almost entirely insensitive to pain, the liver as an organ and the bile ducts are extremely sensitive, as are the bronchi, ureters, parietal pleura and peritoneum. Some pain receptors are selective in their response to stimuli, but most are sensitive to more than one of the following types of excitation: (1) mechanical stress of trauma; (2) extremes of heat and cold; and (3) chemical substances, such as histamine, potassium ions, acids, prostaglandins, bradykinin and acetylcholine. The conscious perception of pain probably takes place in the thalamus and lower centers; interpretation of the quality of pain is probably the role of the cerebral cortex. There are some naturally occurring internal systems in the body that are known to control pain but none of them has been completely verified. One of the best known is the gate control system in which it is thought that pain impulses are mediated in the substantia gelatinosa of the spinal cord.

abdominal p. pain occurring in the area between the thorax and pelvis. Manifestations vary between species. Identifiable syndromes include: (1) horse and camelid—pawing, flank watching, rolling, straddling as though to urinate, lying on the back; (2) cattle—may depress back and paddle with hindfeet but mostly arched back, grunting, immobility; (3) dogs and cats— arched back, grunting, depression, reluctance to move. Sometimes there is elevation of the hindquarters, with the chest and forelegs on the ground (the so-called ‘praying dog’ attitude).

Beagle p. syndrome see steroid responsive meningitis-arteritis.

endogenous p. caused by factors within the body, e.g. stretching of mesentery.

p. hypersensitivity responsiveness to noxious stimuli that produces exaggerated and prolonged pain. May be either peripheral sensitization, which is a reduction in threshold and an increase in responsiveness of the peripheral ends of nociceptors, or central, which is an increase in the excitability of neurons within the central nervous system.

P-1 : Paint horse. From Sambraus HH, Livestock Breeds. Mosby, 1992.

projected p. pathology in one area can affect the nerve supply to a distant area in which pain is experienced.

p. receptors free nerve endings of tufts of fine points or buttons.

referred p. pain felt in an area distant from the site of pathology but not mediated through a common innervation. There is no evidence that referred pain occurs in animals but it seems likely on anatomical grounds.

p. threshold the lowest level at which a stimulus can be applied and cause perceptible pain.

p. tolerance the level of stimulation at which pain becomes intolerable.

visceral p. caused by inflammation of serous surfaces, distention of viscera and inflammation or compression of peripheral nerves. The pain caused by stretching of the wall of a hollow viscus is often intermittent because of its alternating relaxation and spasm in response to distention.

paint [pānt] commercial paint products are used in animal accommodation. Most contain some lead, even so-called lead-free paints. See lead1 poisoning.

paint horse [pānt] see American Paint horse.

paintbrushes see Castilleja.

paired pertaining to data or animals that are matched as being very similar.

p. controls see paired control.

p. data values which fall normally into pairs and can therefore be expected to vary more between pairs than within pairs.

Pajaroello tick see Ornithodorus coriaceus.

pakoein a toxic cycad glycoside found in Bowenia, Cycas etc.

palae(o)- for words beginning thus see pale(o)-.

palatability pleasantness of taste of feed; willingness of animals to eat the feed in preference to others, which may be based on factors other than taste, e.g. smell, appearance, the sound of cows munching on ensilage.

palate [pal′t] the roof of the mouth. The front portion braced by the upper jaw bones (maxillae) is known as the hard palate and forms the partition between the mouth and the nose. The fleshy part arching from the hard palate to the throat is called the soft palate and separates the oropharynx from the nasopharynx. When the animal swallows, the rear of the soft palate swings up against the back of the pharynx and blocks the passage of food and air to the nose. See also soft palate.

cleft p. see cleft lip, cleft palate.

displaced p. the soft palate of the horse, except during deglutition, rests below the epiglottis. It may be displaced and come to lie above the epiglottis, due either to hypoplasia of the epiglottis or paresis of the soft palate.

midline defect of p. see cleft lip.

p. reflexes swallowing caused by stimulation of the palate.

palatine, palatal pertaining to the palate. See also palate.

p. abscess commonly diagnosed in companion birds. Are often accumulations of keratinized cellular debris as a result of a dietary deficiency of vitamin A.

p. fissure narrow gap beside the palatine process of the incisive bone; covered by the vomeronasal organ and pierced by the naso-incisive duct.

p. rugae see rugae palatal.

p. sinus one of the paranasal sinuses connecting with the nasal cavity that is particularly large in ruminants.

p. slit the caudal half of the palate in birds is divided by a median choanal slit.

palatitis [pal″-ti′tis] inflammation of the palate.

palat(o)- word element. [L.] palate.

palatoglossal [pal″-to-glos′l] pertaining to the palate and tongue.

p. arch see palatoglossal arch.

palatognathous [pal″-tog′n-ths] having a congenitally cleft palate.

palatomaxillary [pal″-to-mak′s-lar″e] pertaining to the palate and maxilla.

palatopharyngeal [pal″-to-f-rin′je-l] pertaining to the palate and pharynx.

p. arch see palatopharyngeal arch.

palatoplasty [pal′-to-plas″te] plastic reconstruction of the palate.

palatoplegia [pal″-to-ple′j] paralysis of the palate.

palatorrhaphy [pal″-tor′-fe] surgical correction of a cleft palate.

palatoschisis [pal″-tos′k-sis] cleft palate.

palatum [p-la′tm] [L.] palate.

pale lacking the pink color of normal viable tissue that is perfused with blood.

pale soft exudative pork see porcine stress syndrome.

pale-encephalon the (phylogenetically) old brain; all of the brain except the cerebral cortex and its dependences.

pale(o)- word element. [Gr.] old.

paleocerebellum [pa″le-o-ser″-bel′m] originally, the phylogenetically older parts of the cerebellum; the term is now applied specifically to those parts whose afferent inflow is predominantly supplied by spinocerebellar fibers.

paleocortex [pa″le-o-kor′teks] paleopallium.

paleogenetic [pa″le-o-j-net′ik] originated in the past; not newly acquired; said of traits, structures, etc., of species.

paleokinetic [pa″le-o-k-net′ik] old kinetic; a term applied to the nervous motor mechanism concerned in automatic associated movements.

paleopallium [pa″le-o-pal′e-m] that part of the pallium (cerebral cortex) developing with the archipallium in association with the olfactory system; it is phylogenetically older and less stratified than the neopallium, and composed chiefly of the piriform cortex and parahippocampal gyrus. Called also paleocortex.

paleopathology [pa″le-o-p-thol′-je] study of disease in bodies that have been preserved from ancient times.

paleopulmo [pa″le-o-pul′mo] the functional division of the avian respiratory tract formed by the parabronchi arising from the mediolateral and medioventral bronchi.

paleostriatum [pa″le-o-stri-a′tm] the phylogenetically older portion of the corpus striatum, represented by the globus pallidus.

paleothalamus [pa″le-o-thal′-ms] the phylogenetically older part of the thalamus, i.e. the medial portion which lacks reciprocal connections with the neopallium.

Palicourea [pal″-ko-u′re-] South American plant genus in the family Rubiaceae; contain fluoroacetate, a cause of myocardial damage and sudden death; includes P. aeneofusca, P. grandiflora, P. juruana, P. marcgravii, cafezinho, cafe bravo, erva cafe, erva de rato, roxa, roxinha, roxona, vick.

pali(n)- word element. [Gr.] again, pathological repetition.

palindrome [pal′in-drōm] literally, something that reads the same backwards as forwards. In nucleic acid biochemistry palindromic sequences of 4 to 10 or more base pairs occur not infrequently. These function as recognition sites for cleavage by restriction endonuclease enzymes or secondary structures as the folding of RNA molecules or the hairpin structures found at the termini of the single-stranded DNA genomes of parvoviruses.

interrupted p. restriction enzymes such as BglI recognize sequences which are interrupted palindromes, e.g. GCCNNN↓NGGC where N is any nucleotide.

palindromia [pal″in-dro′me-] a recurrence or relapse.

palisade worms [pal″-sād′] see Strongylus.

palisading giving the appearance of palisades, as in a picket fence.

p. crust alternating horizontal layers of keratin and exudate in a crust or scab.

p. granuloma see palisading granuloma.

palladium (Pd) [p-la′de-m] a chemical element, atomic number 46, atomic weight 106.4. See Table 4.

palliate [pal′e-āt] to relieve clinical signs.

palliative [pal′e--tiv] affording relief; also, a drug that so acts.

pallidum [pal′-dm] the globus pallidus, the medial subdivision of the lentiform nucleus, of the brain.

pallium [pal′e-m] the cerebral cortex viewed in its entirety, i.e. the mantle of gray matter covering both cerebral hemispheres. Also, the cerebral cortex during its development.

pallor [pal′r] paleness, as of the skin or mucosae. Although it is commonly associated with anemia, many long-term cases show mucosae of normal color; pallor is also a common sign in shock.

central p. the lighter staining central area seen in discoid-shaped erythrocytes of dogs.

palm [pahm, pahlm] one of many flowering plants in the family Arecaceae (Palmae); including Elaeis guineensis (oil palm), Phoenix dactylifera (date palm), Cocus nucifera (coconut palm), Caryota mitis (fishtail palm), Metroxylon sagu (sago palm). See also sago palm.

Palma christi [pahl′m] see Ricinus communis.

palmar [pahl′mr] descriptive of the palm of the human hand, or of the homologous surface or direction of the limbs of other animal species.

p. nerve block see plantar nerve block.

palmar-plantar erythrodysesthesia syndrome [pahl′mr] a side effect of some chemotherapy drugs caused by capillary leakage of the drug into tissues, particularly the hands and feet in humans and the paws or feet in animals. Tissue damage results in redness, swelling and blisters. Tingling or burning is reported in humans.

Palmer dental notation [pahl′mr] a scheme for charting the position and number of teeth. A horizontal line indicates the occlusal plane and a vertical line in the middle indicates the midline. The teeth in each quadrant are numbered, starting from the point closest to the midline.

palmitate [pal′m-tāt] salt or ester of palmitic acid, a common dietary fatty acid.

palmitic acid [pal-mit′ik] a 16-carbon saturated fatty acid from animal and 16-carbon vegetable fats, particularly palm oil.

palmitin [pal′m-tin] glycerol tripalmitate, one of the common fats in animal fat. A crystallizable and saponifiable substance.

palmitoleic acid [pal″m-to-le′ik] a 16-carbon monounsaturated, with a double bond at carbons 7,8, endogenously synthesized nonessential fatty acid.

palmityl-CoA-carnitine transferase an enzyme involved in the transport of fatty acids across the mitochondrial membrane.

palmus [pa′ms] 1. palpitation. 2. clonic spasm of limb muscles, producing a jumping motion.

palo santo tree see Bulnesia sarmientii.

palomino [pal-o-me′no] not a breed of horse but a color type of gold with white mane and tail.

palpable [pal′p-bl] perceptible by touch.

palpate [pal′pāt] to perform palpation.

palpation [pal-pa′shn] the technique of examining parts of the body by touching and feeling them.

abdominal p. palpation of the contents of the abdomen and the state of the abdominal wall either through the wall or per rectum.

gastric p. internal palpation of the stomach via the esophagus is performed in dolphins and other cetaceans.

motion p. in chiropractic, examination of the range of movement in vertebral joints.

per-rectal p. palpation of the posterior abdomen and the organs in it by inserting the finger (in dogs) or hand and arm (in horses, cattle and pigs) in the rectum. Called also rectal palpation.

pharyngeal p. palpation via the external wall in small animals; can be performed per os in cattle but requires a mouth speculum for all but the most deft practitioners.

static p. in chiropractic, examination of the vertebral column for alignment and asymmetry and surrounding soft tissues for tone, heat and pain.

palpebra [pal′p-br] pl. palpebrae [L.] eyelid.

palpebra tertia [pal′p-br] third eyelid, palpebra III; membrane nictitans.

palpebral [pal′p-brl] pertaining to the eyelid.

p. conjunctiva conjunctiva lining the inner aspect of the eyelid.

p. commissure see canthus.

p. fissure see palpebral fissure.

medial p. ligament the medial canthal ligament which connects the medial canthus to the orbit.

p. nerve a branch of the auriculopalpebral nerve which innervates the orbicularis oculi muscle of the eyelid and effects eyelid closure. See Table 14.

p. reflex eyelid closure following stimulation of the periocular tissue; requires normal function of cranial nerves V and VII, as well as the orbicularis oculi muscle.

palpebritis [pal″p-bri′tis] blepharitis.

PALS periarteriolar lymphoid sheath. See white pulp.

P-2 : Assessing the palpebral reflex by lightly tapping the medial or lateral canthus.

From Thomas JA, Lerche P, Anesthesia and Analgesia for Veterinary Technicians, 4th Edition. Mosby, 2011.

palsy [pawl′ze] paralysis. A word used commonly in human medicine but rarely if ever in veterinary medicine.

palustrine a toxic alkaloid in Equisetum spp.

Palyam viruses a group of viruses in the genus Orbivirus which cause abortion and congenital abnormalities, including hydranencephaly and cerebellar hypoplasia, in cattle in Africa, Japan and Australia.

PAM, 2-PAM 2-pyridine aldoxime methchloride (pralidoxime chloride).

pamidronate [pam″-dro′nāt] a bisphosphonate used in the management of hypercalcemia and to alleviate osteolytic pain of osteosarcomas in dogs.

pampas grass see Cortaderia selloana.

pampiniform shaped like a tendril, e.g. pampiniform plexus, a plexus of veins which tangle around the tortuous testicular artery.

PAMS p aminosalicylic acid.

pan- word element. [Gr.] all.

panacea [pan″-se′] a remedy for all diseases.

Panaeolina foenisecii see Psilocybe.

panagglutinin [pan″-gloo′t-nin] an agglutinin that agglutinates the erythrocytes of all human blood groups.

panangiitis [pan″an″je-i′tis] inflammation involving all the coats of a vessel.

panaritium an obsolete expression for paronychia. Still used with reference to cattle and meaning bovine footrot.

panarteritis nodosa [pan″ahr″t-ri′tis no-dōs′] see periarteritis nodosa.

panarthritis [pan″ahr-thri′tis] inflammation of all the joints.

panatrophy [pan-at′r-fe] atrophy of several parts; diffuse atrophy.

panautonomic [pan″aw-t-nom′ik] pertaining to or affecting the entire autonomic (sympathetic and parasympathetic) nervous system.

pancarditis [pan″kahr-di′tis] diffuse inflammation of the heart.

pancolectomy [pan″ko-lek′t-me] excision of the entire colon, with creation of an outlet from the ileum on the body surface.

pancreas [pan′kre-s] a large, elongated, racemose gland located in the anterior abdomen between the liver, kidneys, stomach, spleen and duodenum. The pancreas is composed of both exocrine and endocrine tissue. The acini secrete digestive enzymes, and small ductules leading from the acini secrete ions, mainly sodium and bicarbonate. The combined product, pancreatic juice, enters a long pancreatic duct and from there is transported duct to the duodenum. The pancreatic juice contains enzymes for the breakdown of proteins, carbohydrates and fats. The bicarbonate ions in the pancreatic secretion help neutralize the acidic chyme that is passed along from the stomach to the duodenum. The endocrine functions of the pancreas are related to the islets of Langerhans which occur throughout the pancreas. These small islands contain three major types of cells: the alpha, beta and delta cells. The alpha cells secrete the hormone glucagon, which elevates blood sugar. The beta cells secrete insulin, which affects the metabolism of carbohydrates, proteins and fats. The delta cells secrete somatostatin, the functions of which are not fully understood, but it is known that it can inhibit the secretion of both glucagon and insulin and may act as a controller of metabolic processes. The somatostatin produced by the delta cells of the pancreas is the same as that produced by the hypothalamus as an inhibitor of the release of growth hormone from the pituitary gland.

p. disease pancreatic atrophy of post-smolt Atlantic salmon caused by a togavirus infection; clinical signs include anorexia, emaciation. Called also sleeping disease.

pancreatectomy [pan″kre--tek′t-me] excision of the pancreas.

pancreatic [pan″kre-at′ik] pertaining to the pancreas. See also pancreatitis, diabetes mellitus, cystic pancreatic duct.

p. abscess occurs as a complication of acute pancreatitis or subsequent to pancreatic surgery due to bacterial contamination but is most common as an extension from a leaking gastric ulcer.

p. acinar atrophy the islets of Langerhans remain normal but acinar tissue atrophies and exocrine function is compromised. Seen most commonly in large breeds of dogs, particularly German shepherds and Collies. Clinical signs are related to the exocrine pancreatic insufficiency (see below).

acute p. necrosis see acute hemorrhagic pancreatitis.

p. alpha cells alpha cells cells in the islet of Langerhans which secrete glucagon.

p. anomaly includes acinar hypoplasia and congenital Islet of langerhans aplasia.

p. beta cells beta cells comprise the majority of pancreatic islet cell population; secrete insulin.

p. bladder a diverticulum in the pancreatic duct like a gallbladder in the bile duct. Seen in some cats.

p. calculus small concretions, 4 to 5 mm diameter, in the pancreatic ducts, caused by chronic inflammation. Seen, usually in large numbers, in cattle.

p. cysts anomalous obstructions of ducts, often associated with similar cysts in kidneys and bile ducts.

p. delta cells cells in the islet of Langerhans; known to secrete somatostatin.

p. duct one of the two excretory ducts of the pancreas. Depending on the species, it may unite with the common bile duct before entering the duodenum at the major duodenal papilla. Absent from the pig and ox which only have an accessory pancreatic duct (developed from the dorsal primordium) which opens on the minor duodenal papilla. See also bile duct.

p. duct obstruction congenitally by agenesis of the duct, by pancreatic lithiasis or inflammation or neoplasia in the vicinity; causes initial distention followed by atrophy of acinar tissue.

p. ectopic tissue small masses of pancreatic exocrine or endocrine tissue found occasionally in the wall of the stomach or intestines and in the gallbladder; presumed to be functional.

p. enzymes 1. the exocrine secretion into the intestine includes amylase, endo- and exopeptidases, and lipase. The endopeptidases include trypsin, chymotrypsin and elastase, the exopeptidases are the carboxypeptidases A and B. 2. preparations of various pancreatic extracts are used as enzyme replacement thereapy in the clinical management of exocrine pancreatic insufficiency in dogs and cats.

exocrine p. insufficiency (EPI) insufficient secretion of digestive enzymes, usually due to loss of acinar tissue from idiopathic acinar atrophy or acute or chronic inflammation, causes maldigestion and malabsorption with diarrhea, steatorrhea and weight loss.

p. F cells secrete pancreatic polytpeptide; called also PP cells.

p. fibrosis a sequel to pancreatitis, pancreatic duct obstruction, zinc poisoning.

p. gastrinoma a gastrin-producing tumor arising from the delta cells of the pancreatic islets that causes hypergastrinemia, hypersecretion of gastric acid and ulceration of the upper gastrointestinal tract. Occurs rarely in dogs. See also Zollinger-Ellison syndrome.

p. hypertrophy physiological response to diets high in protein and energy.

p. islets islets of cells scattered through the pancreas; contain alpha, beta, C and D cells.

p. islet cell tumor see gastrinoma, insulinoma.

p. lipase enzyme released from the exocrine pancreas; catalyzes the hydrolysis of dietary lipids in the presence of bile salts. See also lipase.

p. lithiasis see pancreatic calculus (above).

p. nodular hyperplasia firm, pale elevations on the surface of the gland; involve only the exocrine tissue; common in old cats and dogs; cause unknown; no discernible effect on patient.

p. polypeptide secreted by the PP cells in the pancreas; regulates endocrine and exocrine pancreatic secretion.

p. trypsin inhibitor see trypsin inhibitor.

pancreatic(o)- [pan″kre-at′ik] word element. [Gr.] pancreatic duct.

pancreaticoduodenal [pan″kre-at″-ko-doo″o-de′nl] pertaining to the pancreas and duodenum.

P-3 : Anatomy of pancreatic islets.

From Guyton AC, Hall, JE, Textbook of Medical Physiology, 11th Edition. Saunders, 2005.

pancreaticoenterostomy [pan″kre-at″-ko-en″tr-os′t-me] anastomosis of the pancreatic duct to the intestine.

pancreaticomesojejunal ligament [pan″kre-at″-ko-me″zo-j-joo′nl] an anomalous structure that extends between the pancreaticoduodenal vein, under the ileum and colon, to the left side of the mesojejunum. Reported to be the cause of diarrhea in kittens.

pancreatin [pan′kre--tin] a substance from the pancreas of the hog or ox containing enzymes, principally amylase, protease and lipase; used in the treatment of pancreatic exocrine insufficiency.

pancreatitis [pan″kre--ti′tis] inflammation of the pancreas; an important disease in dogs and cats.

acute hemorrhagic p. a condition due to autolysis of pancreatic tissue caused by escape of enzymes into the substance, resulting in hemorrhage into the parenchyma and surrounding tissues. Seen most commonly in dogs, rarely in horses and pigs. Clinical signs include abdominal pain that may be severe and associated with cardiovascular shock, vomiting and diarrhea. Fatalities are not uncommon. In the longer term, the process may be slowly progressive, appearing clinically to be relapsing, often with eventual destruction of the islets of Langerhans that leads to diabetes mellitus. Called also acute pancreatic necrosis.

chronic p. relapsing or continuing acute pancreatic necrosis. Called also relapsing pancreatitis.

focal p. focal lesions discovered incidentally in patients dying of other disease, e.g. canine distemper, foot and mouth disease.

interstitial p. inflammation of the interstitial tissue; may be acute or chronic.

necrotizing p. see acute hemorrhagic pancreatitis (above).

relapsing p. see chronic pancreatitis (see above).

pancreat(o)- word element. [Gr.] pancreas.

pancreatoduodenectomy [pan″kre--to-doo″o-d-nek′t-me] excision of the head of the pancreas along with the encircling loop of the duodenum.

pancreatogenous [pan″kre--toj′-ns] arising in the pancreas.

pancreatolithectomy [pan″kre--to-l-thek′t-me] excision of a calculus from the pancreas.

pancreatolithiasis [pan″kre--to-l-thi′-sis] the presence of calculi in the ductal system or parenchyma of the pancreas.

pancreatolithotomy [pan″kre--to-l-thot′-me] incision of the pancreas for the removal of calculi.

pancreatolysis [pan″kre--tol′-sis] destruction of pancreatic tissue.

pancreatotomy [pan-kre-at′-me] incision of the pancreas.

pancreatotropic [pan″kre--to-tro′pik] having a special affinity for the pancreas.

pancrelipase [pan″kre-li′pās] a preparation of hog pancreas containing enzymes, principally lipase with amylase and protease, having the same actions as pancreatic juice; used in the treatment of exocrine pancreatic insufficiency.

pancreolithotomy [pan″kre-o-l-thot′-me] pancreatolithotomy.

pancreolysis [pan″kre-ol′-sis] pancreatolysis.

pancreozymin [pan′kre-o-zi″min] a hormone of the duodenal mucosa that stimulates the external secretory activity of the pancreas, especially its production of amylase; identical with cholecystokinin.

pancuronium [pan″ku-ro′ne-m] a non-depolarizing neuromuscular blocking agent, used as the bromide salt.

pancystitis [pan″sis-ti′tis] cystitis involving the entire thickness of the wall of the urinary bladder, as occurs in interstitial cystitis.

pancytopenia [pan″si-to-pe′ne-] abnormal depression of all the cellular elements of the blood. Results from the depression of activity of bone marrow, spleen and lymph nodes such as occurs in radiation injury and a number of poisonings, e.g. Pteridium aquilinum, trichlorethylene extracted soybean meal, nitrofurans and stachybotrytoxicosis.

bovine neonatal p. an emerging disease of neonatal calves characterized by pancytopenia and bone marrow depletion and manifest with bleeding. Believed due to alloantibodies directed against surface antigens of neonatal leukocytes received in colostrum and induced by maternal vaccination with a BVD vaccine. Called also bleeding calf syndrome.

myelophthisic p. resulting from loss of bone marrow function.

tropical canine p. (TCP) see canine ehrlichiosis.

aplastic p. see aplastic anemia.

pancytopenic relating to pancytopenia.

panda includes the giant panda and red panda (see below).

red p. (Ailurus fulgens) the only living member of the family Ailuridae; not closely related to the giant panda (Ailuropoda melanoleuca) which is in the family of true bears, Ursidae. Native to the Himalayas, it is medium-sized with a dense, red and black coat and long, furry, ringed tail. Called also lesser panda, cat bear.

giant p. (Ailuropoda melanoleuca) in the family Ursidae; native to central China, it has a large bear-like body and short tail. The distinctive black and white coat is widely recognized because of the attention this animal receives in zoo exhibits and media accounts of conservation efforts.

pandemic [pan-dem′ik] a widespread epidemic, i.e the disease is clustered in time but not in space.

Pandy test a screening test for globulin in the cerebrospinal fluid; a positive result is an indication of inflammation in the central nervous system.

panencephalitis [pan″n-sef″-li′tis] encephalitis with parenchymatous lesions of both the gray and white matter of the brain.

sclerosing p. see old dog encephalitis.

panendoscope [pan-en′do-skōp] a cystoscope that gives a wideangle view of the bladder.

Paneth cell narrow, pyramidal or columnar epithelial cell with a nucleus close to its base. Found in the fundus of the mucosal crypts in the intestine.

pangenesis a now discarded hypothesis about heredity stating that the whole organism reproduces itself through all of its parts. The proposed mechanism is based on the supposed existence of gemmules in the blood each of them representing a cell of the body and each of them throws off an atom which is inherited by an offspring.

pangola grass Digitaria decumbens.

Pangonia [pan-go′ne-] a genus of flies in the family Tabanidae; some feed on blood and cause insect worry in horses and cattle. Called also deer fly. Do not suck blood but will mop up spilled blood.

panhypopituitarism [pan-hi″po-p-too′-t-riz-m] generalized hypopituitarism due to absence or damage to the pituitary gland, which in its complete form, leads to absence of gonadal function and insufficiency of thyroid and adrenal function. When cachexia is a prominent feature, it is called Simmonds′ disease or pituitary cachexia.

juvenile p. most frequent in German shepherd dogs but also in other breeds; puppy dwarfism not apparent until 2–3 months old; small stature, delayed dentition, alopecia, infantile genitalia and short life span are characteristic. See also German shepherd dog dwarfism.

panhysterectomy [pan″his-tr-ek′t-me] total hysterectomy.

panhysterosalpingectomy [pan-his″tr-o-sal″pin-jek′t-me] excision of the uterus, cervix and oviducts.

panhysterosalpingo-oophorectomy [pan-his″tr-o-sal″ping-go-o″of-– rek′t-me] excision of the uterus, cervix, oviducts and ovaries.

panic grass [pan′ik] grasses that are members of the genus Panicum, e.g. P. antidotale.

bambatsi p.g. Panicum coloratum var. makarikariense.

blue p.g. Panicum antidotal.

giant p.g. see Brachiaria mutica.

green p.g. Megathyrsus maximum var. pubiglumis (Panicum maximum var. trichoglume).

hairy p.g. Panicum effusum.

panicled redshank Amaranthus cruentus.

Panicum [pan′-kum] a genus of grasses in the family Poaceae. May contain sufficient nitrate or oxalate to cause poisoning with these substances. They are highly productive and popular annual and perennial grasses and cereal crops but many of them cause hepatogenous photosensitization due probably to a high content of steroidal saponins in the plants. Edematous enlargement and icteric staining of the cranial tissues gives rise to the common names of yellow bighead and yellow thickhead. Some contain calcium oxalate crystals and cause equine nutritional secondary hyperparathyroidism. See also Megathrysus.

P. anticum Brachiaria mutica.

P. antidotale may contain sufficient oxalate to cause oxalate poisoning in sheep or osteodystrophia in horses. Also reported as a cause of atypical interstitial pneumonia. Called also blue panic grass.

P. capillare causes nitrate–nitrite poisoning; called alsowitchgrass.

P. coloratum may contain high oxalate or cause hepatogenous photosensitization. Called also Coolah grass, kleingrass.

P. crus-galli reputed to cause photosensitization.

P. decompositum suspected high concentrations of steroidal saponins causing hepatogenous photosensitization. Called also native millet (Australia).

P. dichotomiflorum causes hepatogenous photosensitization due to steroidal saponins; called also smooth witchgrass.

P. effusum causes hepatogenous photosensitization due probably to steroidal saponins. Called also hairy millet.

P. gilvum causes hepatogenous photosensitization due to steroidal saponins. Called also P. laevifolium var. contractum, P. schinzii, sweet grass.

P. maximum see Megathyrsus.

P. miliaceum an annual cereal crop. Causes hepatogenous photosensitization due probably to steroidal saponins. Called also French millet.

P. muticum Brachiaria mutica.

P. purpurascens a coarse, high-producing pasture grass. Called also para grass.

P. queenslandicum causes hepatogenous photosensitization due probably to steroidal saponins. Called also Yabila grass.

P. virgatum causes hepatogenous photosensitization due probably to steroidal saponins.

P. whitei causes hepatogenous photosensitization due probably to steroidal saponins. Called also P. laevinode, pepper grass.

panimmunity [pan″-mu′n-te] immunity to a wide range of bacterial and viral infections.

panleukopenia [pan″loo-ko-pe′ne-] 1. abnormal depression in numbers of white blood cells. 2. the name of a disease caused by feline parvovirus; see feline panleukopenia.

feline p. virus feline parvovirus; the etiologic agent of feline panleukopenia.

p.-like syndrome is characterized by decreased numbers of leukocytes, often an anemia and thrombocytopenia, resembling clinically infection by the feline panleukopenia virus. Occurs in cats infected by feline leukemia virus.

panlife cycle life history; the series of stages in physical which an organism passes through from the primary stage to the germinal stage of adult demise.

panmyeloid [pan-mi′-loid] pertaining to all elements of the bone marrow.

panmyelophthisis [pan-mi″-lof′th-sis] aplastic anemia.

panmyelosis [pan-mi″-lo′sis] proliferation of all the elements of the bone marrow.

feline p. a myeloproliferative disorder seen in cats; associated with infection by feline leukemia virus.

panniculitis inflammation of the subcutaneous fat. See also opportunistic mycobacterial infection.

lobular p. the inflammatory process primarily involves the fat lobules rather than the interlobular connective tissue.

lupus p. see lupus erythematosus.

necrotizing p. multifocal, erythematous, nonpruritic cutaneous lesions which ulcerate in the center and discharge seropurulent exudate; identifiable on histopathological examination.

nodular p. subcutaneous nodules that may become cystic or ulcerate or develop fistulous tracts that drain an oily material. They occur in dogs, cats and horses, and may be sterile or caused by infectious agents.

nodular nonsuppurative p. a disease marked by fever and the formation of tender, sterile nodules in the subcutaneous fatty tissues which drain oily, bloody material. Occurs in dogs, particularly Dachshunds. Similar to Weber–Christian or Christian– Weber disease in humans. Called also sterile panniculitis, or relapsing, febrile, nonsuppurative panniculitis.

postinjection p. occurs after a subcutaneous injection; the characterisitcs depend on the material injected, but range from a discrete nodule with a necrotic center or an area of hair loss with minimal inflammation.

pyogranulomatous p. see opportunist mycobacterial granuloma.

relapsing, febrile, nonsuppurative p. see nodular nonsuppurative panniculitis (above).

septal p. the inflammatory process primarily involves the interlobular connective tissue septae rather than the fat lobules.

sterile p. see nodular nonsuppurative panniculitis (above).

Weber–Christian p. a subcutaneous panniculitis with systemic features. See nodular nonsuppurative panniculitis (above).

panniculus pl. panniculi [L.] a layer of membrane.

p. adiposus the subcutaneous fat; a layer of fat underlying the corium, well developed in pigs and marine mammals.

p. carnosus a muscular layer in the superficial fascia of most quadripedal mammals; it includes the cutaneous trunci.

p. muscle see panniculus carnosus (above).

p. reflex a quick twitch of the subcutaneous muscle along the back in response to a pinprick in the thoracolumbar area. Absence of the reflex is important in helping to localize the location of a lesion in the spinal cord.

pannus [pan′s] 1. chronic superficial keratitis. 2. an inflammatory exudate overlying synovial cells on the inside of a joint capsule, usually occurring in rheumatoid arthritis or related articular rheumatism. 3. panniculus adiposus.

panophthalmitis [pan″of-thl-mi′tis] inflammation of ocular structures and tissues from within all three of the tunics. Compare with endophthalmitis.

panosteitis [pan″os-te-i′tis] 1. inflammation of every part of a bone. 2. a self-limiting disease of young, large breed dogs, particularly German shepherd dogs, characterized clinically by shifting lameness and radiographically by enosteal and subperiosteal new bone formation on long bones. Called also enostosis, juvenile osteomyelitis, and eosinophilic panosteitis or panosteitis eosinophilica, because some cases are reported to have eosinophilia in peripheral blood.

panostosis [pan″os-to′sis] see panosteitis.

panotitis [pan″o-ti′tis] inflammation of all the parts or structures of the ear.

pansinusitis [pan″si-ns-i′tis] inflammation involving all the paranasal sinuses.

pansteatitis [pan″ste″-ti′tis] 1. inflammation of body fat. 2. a disease of cats and aquarium fish fed on a diet high in polyunsaturated fats and low in vitamin E. In cats there is inflammation of all fat tissues; in fish there is also thickening of the swim bladder. See also yellow fat disease.

pansystolic [pan″sis-tol′ik] the whole of systole; includes presystolic and systolic phases. See also heart murmur.

panters atypical interstitial pneumonia of cattle.

panthenol [pan′th-nol] nonproprietary name for pantothenyl alcohol.

Panthera genus in the family Felidae; includes jaguar (P. onca), leopard (P. pardus), lion (P. leo), tiger (P. tigris), and snow leopard (P. uncia).

panting rapid, shallow breathing, a characteristic heat-losing reaction in dogs; represents an increase in dead-space ventilation resulting in heat loss without necessarily increasing oxygen uptake or carbon dioxide loss.

p. disease see atypical interstitial pneumonia, Zieria arborescens.

pant(o)- word element. [Gr.] all, the whole.

pantocaine see tetracaine.

Panton–Valentine leukocidin a nonhemolytic toxin produced by Staphylococcus aureus which kills segmented neutrophils and macrophages.

P-4 : Synovitis and arthritis of hock joints of swine with pannus extending across the articular surface. From Songer JG, Veterinary Microbiology: Bacterial and Fungal Agents of Animal Disease. Saunders, 2004.

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Tags: Saunders Comprehensive Veterinary Dictionary

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

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