Victoria Gregory and Lyndsey Bett Glasgow Equine Hospital and Practice, University of Glasgow, Weipers Centre, Glasgow, United Kingdom The focus of this chapter is the nursing of medical disorders; however, some cross‐over with surgical conditions may occur where more than one form of treatment is an option. Covering every equine medical disorder in detail is beyond the scope of this chapter. Readers are directed to the reference list and further reading section as sources of extra information. Please refer to the glossary for useful information relating to this chapter. A congenital condition is one that a horse is born with. The more common conditions are as follows: These conditions are usually first detected on auscultation of the heart, as an incidental finding, when the veterinary surgeon (vet) is carrying out a routine check and hears a heart murmur. The use of an electrocardiogram (ECG) and echocardiography with Doppler will help to diagnose the severity of these conditions. With VSD and ASD, the larger the defect, the poorer the prognosis, which can lead to death, but small defects may not affect the horse’s life. With PDA, if the ductus arteriosus does not close at all it hinders a horse’s growth. It is rare that PDA is the only congenital problem with the foal’s heart, ruling out surgical repair, unlike cats and dogs, meaning that euthanasia is required. Acquired diseases are conditions affecting the heart that are not present at birth. This is a bacterial infection that causes inflammation of the heart valves or endocardium (the inner most tissue that lines the heart). The bacterial cause may be unknown or be linked to a likely source of bacteria, such as a wound, surgery or an intravenous (IV) catheter. Broad‐spectrum antibiotics should be administered until blood culture results are received. The prognosis is usually poor. Supportive care, such as encouraging the patient to eat and to interact, will help. Administering medications and helping with diagnostic procedures. There may be some nursing care required linked to the bacterial source if known, such as wound care or bandaging. This disease is a degenerative condition that is seen in older horses. The heart valves, commonly the aortic valve, become thickened and fail to close properly allowing for regurgitation. Figure 13.1 Horse wearing an exercise ECG. Source: Victoria Gregory. If no other cardiac problems are present, the horse should be able to continue at the level of work it is doing. For human safety, if the horse is ridden or exercised regularly, an exercise ECG should be carried out to check that the heart can cope when asked to work harder and to confirm that the horse is unlikely to collapse during exercise. Regular checks should be carried out to check the progression of the condition and safety for continued exercise. The pericardial sac surrounds the heart and provides protection and lubrication. A build‐up of fluid in the pericardial sac will reduce the amount of blood able to enter the right ventricle. If the build‐up of fluid is acute, it can cause a condition called cardiac tamponade, where the heart is compressed. This will depend on the amount and aetiology of the effusion. A single‐use catheter can be used for pericardiocentesis which involves draining a small amount of fluid from the pericardial sac and then removing the catheter immediately. Larger quantities of fluid, or fluid‐looking fibrinous on echocardiography, may need a long stay, wide bore tube placed. This tube can be used for drainage, lavage and administering antibiotics if necessary. The tube must be clamped shut when not in use to ensure that air cannot enter the pericardial sac. Echocardiography can be used to monitor the progress of treatment. These are disturbances that can be bradycardic or tachycardic with a regularly irregular rhythm or irregularly irregular rhythm. There is a wide range of disturbances seen in the horse. The following are the most common. This occurs when the atria contracts randomly causing an irregular and sometimes extreme tachycardia. This arrhythmia is described as irregularly irregular as there is no set, predictable pattern associated with it. It may be a primary condition or a clinical finding in a more serious heart condition. Atrial fibrillation may disappear 24–48 hours after exercise or may continue until treatment is started. The longer the condition is left untreated, the harder it is to convert the heart back to a normal sinus rhythm. Quinidine sulphate can cause toxicity in the horse, causing clinical signs such as colic, diarrhoea, ataxia, sweating, tachycardia and these can lead to death, so emergency drugs should be kept close by for immediate administration. The vet will need assistance administering the quinidine sulphate several times over the day, monitoring the ECG continuously, monitoring the patient closely and continuously for toxicity as described above, and if necessary, administering anti‐toxic medications. An IV catheter should always be placed before treatment begins, for rapid venous access [1]. Treatment should stop when the heart has converted to a normal rhythm or toxicity is suspected. The patient will need to wear the ECG monitor for 24–48 hours after the conversion to check that the heart has remained in normal sinus rhythm and should continue to be monitored for quinidine sulphate toxicity after the final dose is administered. Figure 13.2 Catheter placement for TVEC. Source: Dr Claire Dixon. For TVEC, the horse will require a general anaesthetic (GA). A routine jugular catheter will be placed for medication administration as well as electrodes fed through the right jugular to the right atrium and left pulmonary artery (Figure 13.2). Once anaesthetised, the horse will receive shocks at certain points in the ECG trace to encourage the heart to convert back to a normal sinus rhythm. Figure 13.3 shows a horse in lateral recumbency, on low‐level cushions, ready to be shocked. This is a condition often seen in very fit horses at rest. The heart rate will be regularly irregular, missing a beat in a regular rhythm. This is considered a normal variation. The heart rhythm will return to normal with exercise, stress or excitement. Figure 13.3 Patient positioned for TVEC. Source: Dr Claire Dixon. A regular sinus rhythm is heard with the interruption of a premature beat after exercise. If only heard after exercise, this condition is insignificant, but if the premature beat is heard at rest, combined with poor performance or shows signs of other cardiac disease the condition may be of significance. These are less common in horses than atrial arrythmias and are commonly linked to other conditions such as colic, toxaemia, electrolyte imbalances and hypovolemia. If it is possible that the arrhythmia is secondary to a non‐cardiac condition, this should be resolved first. Otherwise, ECG and echocardiography should be performed to reach a diagnosis. This is inflammation of the lymphatic system, commonly seen in hindlimbs and usually associated with a wound. Bacteria can enter the leg via the smallest of abrasions, causing the lymphatic system to become infected. Once a horse has had lymphangitis, it is at higher risk of developing it again, as there is quite often permanent damage to vessels in that area. The horse can also be left with reoccurring or permanent lameness of the affected limb. A registered veterinary nurse (RVN) can administer the medications as directed by the vet and carry out the cold hosing, washing and bandaging of the limb. The limb should be dried before bandaging. The RVN can educate the owner about ongoing care at home and preventative measures to help reduce reoccurrence. This is a malignant form of cancer that affects the lymphoid tissue. Lymphoma is the most common cancer found in the horse. The clinical signs will depend on the site where the lymphoma is present. Horses with cutaneous lymphoma, where no evidence of any other lymphoma can be found, will just have the subcutaneous lesion. The lesion should be surgically removed. For multicentric lymphoma, which involves the lymph nodes, gastrointestinal and mediastinal lymphoma the clinical signs are similar. Long term prognosis is very poor. Chemotherapy and corticosteroids can prolong life but will be costly to the owner. These are benign tumours, made mostly of blood vessels, found in the ethmoid turbinate. Their cause is unknown, and they can reoccur. During surgery, there is a risk of blood loss. The patient may need a blood transfusion and intensive care nursing. During exercise, the soft palate displaces dorsally, above the epiglottis, obstructing the airway. The cause is unknown but can be associated with an underlying respiratory disease, poor fitness (the condition may disappear with improved fitness) or structural abnormalities. If surgery is carried out, the horse will need to be monitored closely during the initial post‐operative period for dysphagia This is when the epiglottis is trapped underneath the subepiglottic and aryepiglottic mucosa rather than sitting on top of it. This is usually seen at rest, but some horses only do it during exercise. Guttural pouch (GP) mycosis is a fungal infection in one or both GPs caused by the Aspergillus species. Fungal plaques are formed, which can erode the wall of the internal carotid, external carotid and maxillary arteries. This may result in the horse bleeding to death. Damage to the cranial nerves may also be seen. Pre‐surgery, intra‐operatively and post‐surgery the horse is at a high risk of a fatal bleed. A blood donor should be on standby, and a blood collection kit should be ready. Some vets will choose to collect the blood in anticipation of needing it in an emergency. Guttural pouch mycosis surgery is classed as a medium‐level emergency [2]. Ideally the horse should be stabilised before the anaesthetic if it has suffered a major bleed but once on site if a bleed starts, surgery should begin to prevent the horse from bleeding to death. Consent for surgery should be sought on arrival at the hospital, and equipment left close to hand should the horse start to bleed. The build‐up of pus in the GP is usually secondary to an upper respiratory tract infection. Horses presenting with GP empyema should be isolated until culture and sensitivity results are back in case it is Streptococcus equi. For the culture and sensitivity testing, a sample of the fluid from the GP can be obtained, using a trach wash tube that will fit down the endoscope. Please refer to Chapter 6 for information on isolation protocols. Exercise‐induced pulmonary haemorrhage occurs in most breeds undertaking intense exercise. It is not understood why these horses have bleeding from the pulmonary capillaries after exercise. Some horses may have inflammation of the airway, upper respiratory tract obstruction or cardiovascular conditions, but others will have no underlying conditions. Equine asthma is a relatively new term for a well‐known condition describing a spectrum of inflammatory respiratory disorders known collectively as inflammatory airway disease (IAD). Mild to moderate equine asthma was previously known as IAD. Severe equine asthma describes what was previously known as recurrent airway obstruction (RAO). Severe equine asthma develops due to an allergy to dust particles, fungal and mould spores or pollen is the common cause of flare‐ups in this disease. The bronchioles become inflamed, fluid can build‐up, which is thicker than normal, and this can cause blockages in the bronchioles. This can then lead to bronchospasms. The disease is a chronic, lifelong condition, but the initial pathology can be reversed and kept under control with the correct management and treatment. If left untreated, the damage to the lungs is permanent. The owner will need a lot of guidance on how to make the horses’ lifestyle as dust‐free as possible. Advice should be given on dust‐free beddings, feeds, stable location (away from straw/hay use and storage), exercise, equine inhaler use, signs of laminitis if on steroids and signs of deterioration. Some practices will have their own advice sheets for this condition. An RVN could visit the yard to offer individual advice. Equine influenza is a highly contagious upper respiratory tract virus that is airborne and passed on by fomites. The epithelium of the respiratory tract becomes swollen, sore and inflamed. Clinical signs appear one to five days after encountering the virus; therefore, any suspected cases should be isolated immediately, and movement of horses in and out of the yard should be halted until a negative result is received. Vaccination against equine influenza helps to prevent the spread of the disease, and vaccinated horses are less likely to suffer severe clinical signs. Prevention of the virus is better than cure, so promotion of the vaccination and clinical signs to owners is important. Good stable ventilation is also an important factor. Infected horses should be monitored for signs of secondary conditions such as pneumonia, pleuropneumonia and myocarditis. The horse will need to be isolated and box‐rested for a long time, so the owner should be advised on how best to stop the horse from becoming depressed. Depending on the yard setup and the number of horses present, the number of entries into the horses’ stable may need to be limited to decrease the risk of spreading the virus. If this is the case when with the horse, interaction is important to prevent boredom and depression. The horse should be groomed regularly. If possible, leave a radio on to provide company and put treat balls or other boredom‐relieving items in with the horse to pass the time. A small holed haynet may help to slow the horse’s eating speed, making forage last longer. EVA is caused by the equine arteritis virus. It is a contagious disease that is notifiable in the United Kingdom; it should be reported to the Animal and Plant Health Agency (APHA). It can be spread by inhalation, venereal transmission, fomites, contact with aborted foetuses and in utero. It is spread mainly by stallions when mating. Stallions can be permanent spreaders in their semen but show no clinical signs. Stallions and mares should be tested before mating; it is recommended that all stallions are vaccinated and mares if mating with a confirmed spreader stallion. All vaccinated horses will appear positive to the virus after administration, so it is important that a negative blood result is recorded before vaccination can take place. These results should be kept in the passport for future reference. Sinusitis can be a primary condition, caused by bacteria or a secondary condition caused by an upper respiratory tract infection or a cheek tooth. It most commonly affects the maxillary and frontal sinuses. Please see Chapter 6 for information about this condition. ARI is a sudden decline in kidney function due to a reduction in blood flow to the kidney. This is usually reversible and a secondary condition to hypovolaemia, gastrointestinal disease, endotoxemia or a side effect to medication. Many of the clinical signs can be mistaken for/confused with other conditions such as colic. This is a progressive and fatal disease; the clinical signs do not usually present until the condition is irreversible. It is usually seen in older horses, it can be a caused by ARI, an immune‐mediated disease or bacterial infection. Once diagnosed, the horse may be stabilised with treatment, but the condition will still progress. Any nephrotoxic medications should be stopped, and corticosteroids may be used to help reduce intrarenal inflammation. Palliative care should be started, encouraging the horse to eat, and offering plenty of water. If the horse is hospitalised, IVFT can be started. Nephrosis is damage to the renal tubules caused by reduced blood flow through the kidneys or nephrotoxins. This condition may lead on to CRF. Presenting signs are the same as for ARI and CRF. Inflammation of the bladder is usually secondary to urolithiasis, catheter placement or cystoscopy. Figure 13.4 A horse undergoing cystoscopy. Source: Victoria Gregory. The stones can be found in the bladder or blocking the urethra. Urethral stones are more common in male horses as their urethra is longer. The stones can be made from calcium carbonate, which will break up easily, or have phosphate in as well, making them harder to break. If the stones are small or breakable, they can be removed during cystoscopy using forceps passed through the biopsy channel in the scope, otherwise surgery will be required. PPID is commonly seen in older horses, but it can affect horses as young as 10 years of age. The nerves in the hypothalamus degenerate, progressively, causing insufficient amounts of dopamine to be produced. If the pars intermedia, in the pituitary gland, does not receive enough dopamine, it cannot control the level of hormones it produces. This results in a high level of multiple hormones being produced, including adrenocorticotropic hormone (ACTH). A dopamine agonist such as pergolide, can be given to balance out hormone levels. To check the horse is receiving the correct dosage, follow‐up haematology samples should be taken to check the ACTH level. The horse should stay on these drugs for the rest of their life, and dosage levels should be checked every year. The ACTH result will differ seasonally; the summer solstice relates to the increase of pituitary activity, and the autumn equinox coincides with the decrease in activity [3]. If the horse has laminitis, this will need to be treated and managed long term. Management changes may be required, such as clipping year‐round if the horse has hirsutism, nutritional changes to help put weight on but not induce laminitis, and the horse’s immune system may be weakened by PPID, making it more important to keep up to date with vaccinations, dental checks and faecal worm egg counts. As the disease progresses, blindness and seizures may occur. Most of these patients will be treated at home, but an RVN can be involved in owner education about the condition, collect repeat haematology samples and assist with long‐term care and support for the patient and owner. EMS is where a combination of insulin dysregulation, obesity and a predisposition to laminitis are evident. It is not known why there is a link between insulin dysregulation and laminitis in EMS. This condition is seen in younger and middle‐aged horses and often seen in native pony breeds, but it can affect any breed. Obesity is not always seen. A lot of these patients will be cared for at home. An RVN can assist with owner education, foot radiographs where laminitis is suspected, diet and exercise advice, weight clinics and body condition scoring at the yard, and long‐term care and support for the owner and patient. This is when the parathyroid glands do not secrete enough parathyroid hormones. Parathyroid hormone regulates and maintains the balance of calcium and phosphorous within the horse; without it, the calcium levels decrease and phosphorous levels increase. It is not known why horses get hypoparathyroidism as a primary condition. Some horses can suffer short term, while others will have the condition for life. Prognosis depends on the response to the initial treatment, but if the horse responds well, the condition can be managed long‐term. Seizures in adult horses may be caused by several different conditions including, but not exclusive to: Seizures in adult horses can be very dangerous so human safety and horse welfare must always be a priority when treating these patients. These vary depending on the type of seizure. Partial or focal seizures affect one part of the body such as facial twitching, limb jerking or self‐harming. Generalised seizures affect the whole body, and the horse may collapse, become incontinent and salivate excessively. If generalised seizures occur in quick succession, this is called status epilepticus. This may depend on any significant known history, such as clinical signs leading up to the seizure, head trauma or known toxicity ingestion. Only if safe to do so, diagnostics may include a CT scan, radiographs, a haematology sample to check complete blood count, electrolytes, specific toxicity, a neurological examination or acquisition of cerebrospinal fluid for analysis. Human safety is paramount when a horse is having a seizure; ideally, a horse should not be approached unless emergency medication needs to be administered. Personal protective equipment (PPE) should be worn in this case, such as a hard hat and steel‐toe cap boots. A visual check on entry and exit points should also be carried out before entering the stable, and any plans or concerns should be voiced so that the whole team knows what the plan is and what might go wrong. To control a seizure, diazepam, phenobarbital and pentobarbital may be administered. If a primary condition is diagnosed, this condition should be treated appropriately. For horses who seizure regularly, oral anticonvulsant medications can be prescribed, but this can be costly to the owner. CVSM, also known as Wobblers syndrome, cervical vertebral malformation and cervical vertebral stenosis, is a developmental condition that causes compression of the spinal cord by the cervical vertebrae. This can be caused by static lesions, which are vertebrae of an abnormal formation and shape, or dynamic lesions, where the vertebrae move abnormally in relation to the other vertebrae. With static lesions, ataxia may be constant but with dynamic lesions ataxia may only be seen when the horse flexes its neck. Clinical signs usually appear between the ages of six months and three years in horses that have a faster growth rate. Tetanus is a bacterial infection caused by toxins that are produced by Clostridium tetani found in soil. It enters the body via a wound, commonly a puncture wound in the sole of the foot. The toxin travels to the spinal cord where it binds irreversibly to motor neurons and causes spasticity. Tetanus progresses rapidly once signs appear. Horses should be vaccinated against tetanus, and this will help their chance of survival should they contract tetanus. Horses are diagnosed from the clinical signs and their history. If no obvious wound is found, the horse’s feet should be checked carefully for hidden puncture wounds. Diagnosis can be confused with colic and laminitis when no wound is found. If diagnosed early the horse can survive but once recumbent the prognosis is very poor. Horses should be stabled in a quiet and dark area away from other horses to avoid stimulation. Feed and water should be offered at chest height so that the horse does not need to stretch for them. Offering food and water at intensive care checks is recommended in case the horse is unwilling to move to the bucket. When entering the stable and handling the horse, the RVN should be quiet and calm but make the horse aware of their presence. If recumbent, the horse will need a very deep bed to try to prevent sores and decubitus ulcers. Pillows or blankets can be placed on the bed to try to prevent trauma to the head and eyes. Food and water should be offered unless dysphagic. Assisted feeding via a nasogastric tube may be required. The patient may need to be managed in a sling. The reader is directed to the Further Reading section for more information. This usually occurs because of trauma such as rearing over backwards, pulling backwards when tied up, colliding at speed with an object or another horse in the paddock, or falling when jumping. This can cause a fracture of the vertebrae, inflammation around the spinal cord from swelling, haemorrhage, oedema or conditions that develop later, such as arthritis and instability. The type of neurological signs displayed by the horse may indicate which part of the spine is damaged. A cervical fracture or damage to the spinal cord in that area may cause ataxia, weakness or paralysis in all four limbs. Thoracic and lumbar injuries may display as ataxia, weakness or paralysis of the hindlimbs and sacral damage can show signs such as incontinence, hindlimb ataxia, weakness, paralysis and loss of tail tone. There may also be an obvious lesion where the horse is injured. Minor traumas may not require much nursing care, but if working around ataxic/weak horses, handlers should always work in pairs and be aware that the horse may fall over or collapse. More severe, recumbent cases will require around‐the‐clock care with regular feed and water offered, assistance to stand with a sling if appropriate and facilities allow, trying to prop the horse in sternal recumbency and changing from left to right lateral recumbency if able. A urinary catheter may be placed to relieve pressure from the bladder and keep the patient dry. Faeces should be removed regularly for hygiene reasons. The head should be protected with a trauma hat or an adapted, and padded headcollar, to prevent further damage. The eyes should be protected from scratches from the bedding. Human safety must always come first when working with neurological and recumbent horses. Equine grass sickness is a disease of unknown cause that affects the nervous system. Previous suggested causes include poisonous plants, bacterial toxins, insects, fungi and viruses. It is currently believed that toxins produced by the bacterium Clostridium botulinum type C may be involved. The most severely affected part of the nervous system is the enteric nerves, which control peristalsis within the gastrointestinal system. It does affect other parts of the autonomic nervous system too; it stimulates salivation controlled by parasympathetic nerves, and within the sympathetic nervous system, it increases the heart rate, inhibits gastrointestinal secretion and promotes adrenaline and noradrenaline release. There are three categories of grass sickness cases: acute, subacute and chronic. About 45–55% of chronic cases will survive, but 100% of acute and subacute cases will be fatal [7]. Although the cause is unknown, some paddocks are known to be linked with several cases of grass sickness. Stabled horses, with no access to pasture, have also been known to have grass sickness. Any horse can be affected by grass sickness, but the most vulnerable categories are horses within the age range of 2–7 years, native Scottish breeds and horses that are overweight. If a paddock has been linked to grass sickness previously, care should be taken if using it for horses in these vulnerable groups. Many grass sickness cases can present like a colic, especially the acute and subacute cases. There are also a wide range of clinical signs, this list will work from most severe to mild signs A definite diagnosis can only be made by examining nerve cells from an ileal biopsy or cranial cervical ganglia. The ileal biopsy can be taken standing or under a GA; a GA will be chosen if there is a need to rule out a type of surgical colic. The cranial cervical ganglia can only be accessed at post‐mortem. Many other tests and information can be used and put together to rule out other conditions and assume grass sickness, but insurance companies may insist on a biopsy to confirm the diagnosis. Other suggestive diagnostic indicators include: Acute and subacute cases should be euthanised as soon as a diagnosis has been made. This may require waiting a couple of days for biopsy results or may be decided using the horses’ presenting signs. If awaiting a biopsy result or owner decision to euthanise, the horse should be made comfortable and treated for the clinical signs it is showing, but the welfare of the horse must come first. Treatment for chronic cases will vary massively as each case is very different but can include: The RVN plays a key part in the initial work‐up, running laboratory tests, setting up equipment and assisting the vet. The most important part of recovery for a chronic case of grass sickness is the nursing care. This may be required within a hospital setting, or for very mild cases and low‐budget cases; it may be the owner caring for the horse at home. Some cases require nursing care for more than a year. The owner must be aware of this, willing to care for the horse and willing to learn how to care for the horse, often taught by the RVN. Grass sickness patients can require very intensive, around‐the‐clock care for long periods of time; nursing care plans and care bundles are a great aid in the recovery of this type of patient, see Section 13.4 for more information. The level of nursing care required will be dictated by the patient and may change frequently but can include and is not limited to: Colic is a generalised term used to describe abdominal pain in horses. It can occur due to many different reasons. See Table 13.1 for different types and causes of colic. These may vary from very mild and only noticeable because the owner knows the horse so well, to extremely dangerous. Clinical signs of colic can include, but are not limited to the following: Table 13.1 Different types and causes of colic. Source: Victoria Gregory. Depending on the cause of colic the treatment may be medical or surgical. Surgical patients will require medical support after their surgery. The cause of the colic will also determine what treatments are required. RVNs play a vital role in the work‐up and care for colic patients. During the work‐up and under direction of the vet, the RVN can run laboratory samples, prepare sites for ultrasound and abdominocentesis, and pass the nasogastric tube to check for reflux. If surgery is indicated, a circulating RVN will be required in theatre and possibly one more RVN will be required to assist with the surgery. For medical care, the RVN can place the IV catheter and be responsible for monitoring it, carrying out intensive care checks, setting up and monitoring the IVFT rate requested by the vet and change the fluid bags when required, administer medications as directed by the vet, ice the feet, change the abdominal bandage and reflux or administer enteral fluids. This list is not exhaustive and will differ dependent on the diagnosis. For information relating to the stabilisation of colic patients prior to surgery, see Chapter 10. For information regarding the care of patients following colic surgery, see Chapter 14. Colitis is inflammation of the colon. Colitis X is a term used to describe an acute, toxic form of colitis with no known cause. Colitis X may be used until a cause of the colitis is known. Colitis X has a guarded prognosis with a high fatality rate. All colitis cases should be treated in isolation until infectious and zoonotic disease test results are confirmed to be negative. Figure 13.5 Example of an intensive care record sheet. Source: Sammie Feighery & Dr Alexandra. G. Raftery. The RVN plays a vital role in the work‐up and inpatient care of these cases. Please see the colic section for more information on this. The tail can be protected from getting covered in faeces by plaiting it up and covering it with a rectal sleeve. The hindlimbs will need to be cleaned daily, and a barrier cream will be applied to prevent skin scalding. The faecal output should be monitored closely, and antidiarrheal medications should be stopped when the diarrhoea stops. Strict isolation measures should be adhered to until an infectious or zoonotic disease has been ruled out. Please refer to Chapter 6 for information on isolation protocols. Choke is an obstruction of the oesophagus usually caused by feed material. This can be caused by eating dry feed too quickly, poor chewing due to dental problems or narrowing of the oesophagus from a previous trauma. Horses can choke on grass, so horses that are turned out permanently are also at risk. If the choke episode has been going on for a long time, the horse may be dehydrated and require IVFT. In severe cases, there may be damage to the oesophagus, which can be seen once the choke has cleared. All choke cases should be starved for 12 hours after the incident. If possible, the endoscope should be repeated the following day to check for damage to the oesophagus, which may lead to further choke or aspiration pneumonia. If damage is suspected, the oesophagus can be imaged using ultrasound and radiographs taken, after the administration of barium, to see if there are any strictures or damage to the oesophagus. In cases of choke that are unable to be resolved medically, there is an option to perform a surgery called an oesophagostomy. This involves making an incision into the oesophagus and removing the food material. The patient will then need a feeding tube placed until the oesophagus has healed and the horse can eat again. This surgery can cause strictures, increasing the risk of choking in the future. This surgery also carries a high risk of infection due to the opening of a dirty body cavity. Once refeeding starts, the horse should be monitored closely for any signs of choking or nasal discharge. The horse should be fed sloppy fibre nut mashes to start, which are very easy to swallow, and then grass can be introduced before hay. If the horse requires IVFT or treatment due to oesophageal damage or aspiration pneumonia, a higher level of nursing care within the hospital will be required. Diarrhoea can be a primary or secondary condition. It may be caused by stress, diet change, parasites, colic, antibiotics, NSAIDs, sand ingestion, anaphylaxis and bacterial infection along with many other reasons. In most cases diarrhoea will self‐resolve before a diagnosis is made and a diagnosis may never be found. More severe cases can be fatal. This will depend on the cause of the diarrhoea. If the horse was already receiving antibiotics or NSAIDs, these should be stopped. If the onset is acute and the cause unknown, the horse should be treated as having Colitis X. If chronic or acute, anti‐diarrheal medications and transfaunation can commence while awaiting test results. IVFT may be required and the administration of plasma or synthetic colloids if hypoproteinaemia develops. Other treatments will depend on the findings during the work‐up. The horse should have their backend cleaned at least twice daily and barrier cream should be applied to the hind limbs. If willing and allowed to eat, soaked hay and soaked fibre nuts should be offered. If the horse is dehydrated, it may need to have IVFT and therefore careful IV catheter management will be required. Faecal output should be monitored closely, and anti‐diarrheal medications stopped when the diarrhoea resolves. Salmonellosis is an infectious and zoonotic disease caused by the bacteria Salmonella; strict isolation protocols must be always followed; please refer to Chapter 6 for information on isolation protocols. The bacteria can be spread by water, feed, wildlife on the yard, equine carriers that do not show any symptoms, humans and surfaces contaminated by infected faeces. Stressed horses with compromised immunity are at a higher risk of being infected; this is a major factor in nosocomial cases. Severe cases of salmonellosis can be fatal, but so can the secondary conditions caused during the acute phase of the disease. Please see the ‘nursing care’ section for Colic and Colitis X for more information on this. Strict isolation protocols must be adhered to when nursing zoonotic cases; contact must only be made with the patient when necessary. Any human showing signs of salmonellosis while nursing an infectious case should contact their doctor immediately and self‐isolate. The ovaries can become enlarged due to the presence of tumours such as Granulosa cell tumours and cystadenoma. Both are slow‐growing, benign and usually unilateral. With cystadenoma, the ovary is not usually hormonally active, but the other ovary is normal. With granulosa cell tumours the ovary is usually hormonally active, and the mare may show behavioural abnormalities, including aggression. The other ovary is normally small and inactive but can be normal. In both cases, the ovary with the tumour should be removed. Ovaries naturally become enlarged during pregnancy, so pregnancy must be ruled out if an enlarged ovary is found. Abnormally small ovaries and infertility can be caused by chromosomal abnormalities, old age, PPID and EMS. The ovary size can be palpated on rectal examination. In male horses, testicles can be retained in the abdomen and not descend into the scrotum; this is called a cryptorchid. It is normal for the testicles to have descended by one year of age, but it may take a bit longer. One or two testicles can be retained. If retained, the testicle does not usually develop properly, and growth is hampered. Retained testicles still produce hormones and can produce fertile semen. If a male horse, who is thought to be gelded, is showing stallion‐like behaviour, they may have an abdominal testicle. A haematology sample should be taken by the vet to test the oestrone sulphate or testosterone levels in the blood; the age of the horse will decide which test is used. Abdominal testicles can be removed understanding sedation using a laparoscope, to find and identify the testicular tissue for removal or under general anaesthesia. Normal anatomy and function of the ovaries and testes can be found in Chapter 4. More information on the surgery involved for retained testicles can be found in Chapter 12. In some stallions, the spermatic cord can be rotated without causing any pain. This can be an incidental finding on palpation that might cause a decrease in sperm production. If the stallion has a testicular torsion the spermatic cord is usually twisted more than 180 degrees, affecting the blood flow to the testicles and clinical signs can be seen. These signs may be an enlarged and painful scrotum, and signs of colic. Unilateral castration of the affected testicle is usually required. Masses on the penis and prepuce are quite common in horses. Clinical signs can include visual masses, foul‐smelling smegma, difficulty urinating, urine spraying in an unusual direction during urination or dribbling urine, and not retracting the penis. The most common tumour is squamous cell carcinoma, but it can also be warts, sarcoids, melanomas, papillomas, lipomas and fibromas. Depending on the size, position and cause of the mass will decide the treatment. A biopsy can be taken and submitted for histology before treatment or the whole mass may be submitted after removal. Some masses can be removed from the area, but others may require the horse to have a partial or full phallectomy. Inflammation of the prepuce and scrotum can be caused by trauma, especially in breeding stallions and infections. Prolapse, or paraphimosis, of the penis can be caused by trauma, neurological disease, exhaustion and the use of phenothiazine derivatives such as acepromazine. When the penis does not retract, venous blood flow is affected causing oedema and if left untreated ulcers, infections and necrosis can occur. The penis, and sheath, should be cleaned, cold‐hosed, moisturised, massaged and placed into a sling to support the weight of the penis and encourage blood flow. A sling can be made from human tights or a combination of bandage materials. Care should be taken to ensure that the sling does not cause further problems, such as sores between the hind legs or on the horse’s back. The horse may require medications such as anti‐inflammatories, diuretics or antibiotics depending on the cause and severity. The vulva sits directly below the anus and should be vertical. Most of the vulva should be lower than the level of the pelvic bone. If the anus is sunken, the vulva tilting off vertical or the vulval lips are flaccid, this increases the risk of faeces, air and bacteria entering the vagina and uterus. This can lead to infections and infertility. During pregnancy, if the vulval conformation is poor, this again can lead to infection and abortion. A Caslick vulvoplasty surgery, during pregnancy, can help to reduce the risk of this happening in high‐risk mares. A severe loss of body weight, old age, overbreeding and the overuse of Caslick vulvoplasty can all contribute to a poorer conformation of a mare’s vulva. A recto‐vaginal fistula (RVF) can be a congenital anomaly seen in foals but is usually caused during foaling. During foaling, a hole is created in the dorsal vaginal wall, which communicates with the rectum, caused by a foal’s hoof. Clinical signs include faecal matter being seen when urinating, vaginal bleeding and incontinence. A diagnosis can be made on visualisation of the fistula. If the fistula is quite far into the vagina, an endoscope may be needed to assess the tear. The mare should be started on NSAIDs and antibiotics. Surgery will be required but this may be delayed for several weeks dependent on the amount of trauma caused to the mare’s vagina. The surgery is likely to be more successful once the swelling has decreased. The mare should be fed a laxative diet pre‐ and post‐operatively to decrease the risk of further tearing. Exertional rhabdomyolysis, commonly known as tying‐up, is a condition affecting the muscles of the horse after being exercised beyond its’ fitness level. It can be seen during the event or immediately after. The muscles cramp commonly the hind quarters, causing a lot of pain, stiffness and muscle breakdown in the horse. These horses are usually dehydrated as well. The severity of the episode will correlate with how much nursing care is required. The more severe cases will require lots of intensive care nursing, haematology samples to assess hydration and muscle recovery, and checks. If they are recumbent, they will need to be kept comfortable, clean and dry, warm, propped into sternal and offered water and food regularly. Care should be taken to protect the head and eyes when recumbent. Equine polysaccharide storage myopathy presents the same as exertional rhabdomyolysis, but the horse has not usually undertaken much exercise, and the condition returns regularly and is progressive. It can be diagnosed on muscle biopsies, which show abnormal levels of glycogen being stored in the muscles and genetic testing. The condition can be managed with an altered diet that is low in digestible carbohydrates and higher in fat, along with a daily exercise routine with suitable warm‐up and warm‐down exercises. Rest days, stress and a disruption to routine will all increase the risk of muscle cramping. Azoturia is like exertional rhabdomyolysis but is usually linked to nutrition and rest. Horses at high risk are those that are fed the same high‐energy diet on their rest days. The clinical signs, diagnosis and treatment are the same as exertional rhabdomyolysis. Atypical myopathy is a fatal disease caused by the ingestion of sycamore seeds, leaves or seedlings. It is a seasonal condition seen when the seeds fall during autumn and winter and germinate in the spring. The horses are poisoned by the hypoglycin A toxin, which slows and stops energy production in the muscles. Horses should be removed from pasture with access to sycamore during spring and autumn to prevent atypical myopathy. These patients will require lots of nursing care. They will require intensive care checks, with regular medication administration, IV catheter care, IVFT administration, pain monitoring, urine and faecal output monitoring and repeat haematology samples. If recumbent, the horse will need a very deep bed to try to prevent decubitus ulcers. Pillows or blankets can be placed on the bed to try to prevent trauma to the head and eyes. Food and water should be offered at checks, in case the horse is unwilling, or unable, to move to the bucket. If a horse survives the first few days of treatment, this improves the prognosis. Laminitis is inflammation of the laminae tissue in the hooves, which attaches the pedal bone to the hoof. This inflammation can be caused by several different factors, such as systemic toxicity, metabolic disturbances, steroid administration and excessive weight bearing due to an injury on a contralateral limb. Once the inflammation has occurred the laminae becomes weak allowing for rotation and sinking of the pedal bone. This condition is extremely painful and becomes terminal if the pedal bone sinks through the bottom of the foot. It can affect one or multiple feet. Pain management will be a big part of the recovery for horses with laminitis, along with treatment of any primary condition. They will need intensive care checks with regular pain scoring, faecal output monitoring as they will be at risk of impaction colic, repeat radiographs to see the progression of the disease, and assessment of their pain regularly throughout the day. Due to long periods of time spent on box rest, environmental enrichment will be required. Transportation is a painful and stressful event for a laminitic patient; discharge from the hospital may take longer than planned, as the horse will need to be fit to travel. Horses who suffer from an episode of laminitis will always be at risk of having another. RVNs can help to educate owners on preventative measures and long‐term management changes. Navicular disease is a progressive condition causing degeneration of the navicular bone. It usually affects both front feet. The cause is not known, but it is known that it can be hereditary. It is thought to be linked to conformation, foot balance and damage to the soft structures surrounding the navicular bone. Navicular syndrome is a generalised term for lameness, diagnosed by nerve block and radiographs, in the heel area of the foot. Now that magnetic resonance imaging (MRI) is available, the damage to the different soft and bony structures can be individually identified and diagnosed. The condition can be managed, and slowed down, but not cured. The horse may be able to return to a lower level of work, but consistent, hard work usually worsens the condition. In adult horses, joint or tendon sheath infections are caused by bacteria entering via a wound or injection site. The wound can be a puncture wound, from a thorn, so it is important to clip the area and look for any evidence of a bacterial entry point if there is no obvious wound. Foals can have systemic sepsis, where bacteria is circulating in the blood, which causes multiple joint sepsis with no wounds. See Chapter 15 for more information. Ideally, an arthroscopic examination of the joint, under GA, to flush bacteria and debris out within 24 hours of the wound happening, to increase the chances of recovery. Under GA, the surgeon can also assess any damage in the surrounding area. A standing flush, under heavy sedation, is an option if funds or facilities are limited, but this will decrease the chance of recovery. Repeated surgeries may be needed to eradicate the infection, and still may not cure the horse, resulting in euthanasia. A septic structure left untreated will result in euthanasia due to the amount of damage the infection can do, and the amount of pain that the horse will be in. The surgeon will require assistance in the workup of the horse, to help with radiographs, lab tests, clipping and prepping the site and obtaining the relevant samples. A circulating RVN will be required during surgery, GA or standing and RVNs can change the bandage in the days following surgery and help if repeated samples or imaging is required. Foals can be born with a condition called entropion, where the eyelids roll inwards causing the hairs to rub the cornea. This can be easily resolved by placing sutures at the lid margin to unroll the eyelid. Tumours are common in horses’ eyelids, these may be sarcoids, squamous cell carcinomas, melanomas or mast cell tumours. Tumours in the eyelid are not usually noticed until they are quite large. Diagnosis can be made by taking a biopsy of the lump, or diagnosis and treatment may be combined with the tumour being surgically removed and sent away for histopathology. Other treatments may include cryotherapy and chemotherapy. Whichever method is chosen, extreme care must be taken to avoid damaging the eye. Inflammation of the conjunctiva is common in horses. The cause can be primary or secondary, and the condition can be unilateral or bilateral. Primary causes include foreign bodies, trauma, flies during the summer months and allergens. Secondary causes can be corneal ulcers, uveitis, blocked nasolacrimal ducts and systemic viral and bacterial infections. This will vary dependent on the cause of the conjunctivitis but may include antibiotic and anti‐inflammatory eye drops. A corneal ulcer is an inflammatory condition that causes disruption to the epithelial layer of the eye. The ulcer is usually caused by a trauma but can be due to a secondary infection. Horses with corneal ulcers should be seen as an emergency case. Corneal ulcers can lead to enucleation. Secondary uveitis is common, so this should be investigated and treated if diagnosed. Corneal ulcers in well‐behaved or less painful horses can be treated topically with antibiotics, serum, EDTA and systemically with NSAIDs. Difficult or painful horses and more severe ulcers may require a subpalpebral lavage system to be placed to administer medications easily and frequently to the cornea (see Figure 13.6). Treats may still be required to make the administration of medication into a positive experience for the horse. Regular examinations of the eye should be carried out to monitor for any improvement or deterioration of the ulcer, every two to three days. The ulcer may need debriding, or a keratotomy may be beneficial to help with healing. In severe cases, surgery to perform a conjunctival graft or enucleation may be required.
13
Medical Nursing and Patient Care
Glossary
Introduction
13.1 Commonly Encountered Medical Disorders
Circulatory Disorders
Congenital Heart Disease
Acquired Heart Disease
Endocarditis
Clinical Signs
Diagnostics
Treatment
Nursing Care
Endocardiosis
Clinical Signs
Diagnostics
Treatment
Pericardial Effusion
Clinical Signs
Diagnostics
Treatment
Arrythmias
Atrial Fibrillation
Clinical Signs
Diagnostics
Treatment
Nursing Care
Second Degree Atrioventricular Block
Clinical Signs
Diagnostics
Treatment
Atrial Premature Contractions
Clinical Signs
Diagnostics
Treatment
Ventricular Arrythmias
Lymphatic System Disorders
Lymphangitis
Clinical Signs
Diagnostics
Treatment
Nursing Care
Lymphoma
Clinical Signs
Diagnostics
Treatment
Respiratory Disorders
Nasal, Laryngeal and Soft Palate Disorders
Progressive Ethmoid Haematoma
Clinical Signs
Diagnostics
Treatment
Nursing Care
Dorsal Displacement of the Soft Palate
Clinical Signs
Diagnostics
Treatment
Nursing Care
Epiglottal Entrapment
Clinical Signs
Diagnostics
Treatment
Guttural Pouch Mycosis
Clinical Signs
Diagnostics
Treatment
Nursing Care
Guttural Pouch Empyema
Clinical Signs
Diagnostics
Treatment
Airway Diseases
Exercise‐induced Pulmonary Haemorrhage
Clinical Signs
Diagnostics
Treatment
Equine Asthma
Clinical Signs
Diagnostics
Treatment
Nursing Care
Equine Influenza
Clinical Signs
Diagnosis
Treatment
Nursing Care
Equine Viral Arteritis (EVA)
Clinical Signs
Diagnosis
Treatment
Sinusitis
Clinical Signs
Diagnostics
Treatment
Equine Herpes Virus
Urinary
Acute Renal Injury (ARI)
Clinical Signs
Diagnostics
Treatment
Chronic Renal Failure (CRF)
Clinical Signs
Diagnostics
Treatment
Nephrosis
Clinical Signs
Diagnostics
Treatment
Lower Urinary Tract Disease
Cystitis
Clinical Signs
Diagnostics
Treatment
Urolithiasis
Clinical Signs
Diagnostics
Treatment
Endocrine Disorders
Pituitary Pars Intermedia Dysfunction (PPID)
Clinical Signs
Diagnostics
Treatment
Nursing Care
Equine Metabolic Syndrome (EMS)
Clinical Signs
Diagnostics
Treatment
Nursing Care
Hypoparathyroidism
Clinical Signs
Diagnostics
Treatment
Neurological Disorders
Seizures
Clinical Signs
Diagnostics
Treatment
Cervical Vertebral Stenotic Myelopathy (CVSM)
Clinical Signs
Diagnostics
Treatment
Tetanus
Clinical Signs
Diagnosis
Treatment
Nursing Care
Spinal Disorders
Clinical Signs
Diagnosis
Treatment
Nursing Care
Equine Dysautonomia (Grass Sickness)
Clinical Signs
Diagnosis
Treatment
Nursing Care
Gastrointestinal Disorders
Colic
Clinical Signs
Diagnosis
Cause of colic
Description of colic
Treatment options
Diaphragmatic hernia
When the intestines go through the diaphragm into the thoracic cavity
Some cases can be managed medically suffering low grade bouts of reoccurring colic, but most require surgical intervention
Gastric impaction
Food material impacted in the stomach
Medical treatment is the only option due to the location of the equine stomach
Gastric ulcers
Squamous and glandular ulcers found in the stomach
Medical treatment
Parasitic burden
Impactions or damage to the wall linings of the intestines
Medical or surgical dependent on the extent of the burden
Spasmodic colic
Spasms within the intestines
Medical
Strangulating lipoma
The stalk of the lipoma wraps around a piece of intestines, cutting off the blood supply to it
Surgery to remove the lipoma and possibly resect affected intestines
Ileal impaction
Food material blocks the ileum causing gas and fluid to build up in front of the blockage
Surgery to massage the material into the large intestines
Ileocaecal intussusception
This invagination of the ileum can be caused by small masses, foreign bodies or a parasitic burden
Surgery with resection likely
Epiploic foramen entrapment
Small intestines get stuck in the epiploic foramen
Surgery to release the small intestines
Enteritis
Inflammation of the small intestines
Medical but surgery may be required to rule out other types of colic
Tympanic colic
Gas builds up in the large intestines
Medical treatment with enteral fluids and gentle exercise. If still painful surgery may be required
Caecal impaction
Impaction of the caecum
Medical with IVFT and enteral fluids. These are at high risk of rupturing their caecum so surgery should be carried out if the patient is extremely painful or the impaction is very large
Caecal intussusception
The apex of the caecum invaginates due to motility problems. This can include just the caecum or continue to the right ventral colon
Surgery
Pelvic flexure impaction
Impaction at the pelvic flexure where the diameter of the intestines decreases suddenly
Attempt to clear medically with enteral fluids first but surgery if no improvement or pain uncontrollable
Left dorsal displacement of the large colon/nephrosplenic entrapment
The large colon gets trapped over the nephrosplenic ligament, sitting between the spleen and the body wall
Medical attempts using phenylephrine to shrink the spleen and then gentle lunging exercise to encourage the large colon back into its’ normal position. Surgery if not able to correct medically, to replace the large colon to its’ correct position
Right dorsal displacement of the large colon
Large colon sits between the caecum and body wall
Some respond to medical management, but most require surgical intervention to replace the large colon to its’ correct position
Large colon impaction
Impaction of food in the large colon
Medical with IVFT and enteral fluids. This may take several days so close monitoring is required. Increased pain levels, heart rate and peritoneal fluid changes indicate the requirement of surgery
Large colon volvulus
The large colon twists on itself, cutting of the blood supply. The severity depends on the degree of the twist
Surgery to untwist the large colon
Sand impaction
The horse ingests sand, and it accumulates in the large intestines, it can also be abrasive to the intestines
Medical treatment in mild cases but surgery is often needed to remove the sand
Peritonitis
Infection in the peritoneal cavity
Medical or surgical depending on the severity of infection
Treatment
Nursing Care
Colitis X
Clinical Signs
Diagnosis
Treatment
Nursing Care
Choke
Clinical Signs
Diagnosis
Treatment
Nursing Care
Diarrhoea
Clinical Signs
Diagnosis
Treatment
Nursing Care
Salmonellosis
Clinical Signs
Diagnosis
Treatment
Nursing Care
Reproductive Tract Disorders
Endocrine Abnormalities
Disease of Testes, Penis and Prepuce
Abnormal Vulval Conformation
Recto‐vaginal Fistula
Musculoskeletal Disorders
Exertional Rhabdomyolysis
Clinical Signs
Diagnosis
Treatment
Nursing Care
Equine Polysaccharide Storage Myopathy
Azoturia
Atypical Myopathy
Clinical Signs
Diagnosis
Treatment
Nursing Care
Laminitis
Clinical Signs
Diagnosis
Treatment
Nursing Care
Navicular Disease
Clinical Signs
Diagnosis
Treatment
Tendon Sheath and Joint Infection
Clinical Signs
Diagnosis
Treatment
Nursing care
Disorders of the Sense Organs
Ocular Conditions
Eyelid Abnormalities
Conjunctivitis
Clinical Signs
Diagnosis
Treatment
Corneal Ulceration
Clinical Signs
Diagnosis
Treatment
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