Veterinary · Clinical · also Exotic Animal Medicine
Rabbits, rodents, ferrets, parrots and reptiles: disease caused by poor husbandry, safe handling and anaesthesia, their common conditions, and the zoonoses they carry.
In the exams: NAVLE other small mammals 3.3%, pet birds 2.3% and reptiles 1.5%; SAVC exotic pets and cage birds 10
Exotic pet medicine is the veterinary care of the animals people keep at home that are not dogs, cats or farm livestock: rabbits, rodents and ferrets; parrots, canaries, finches and falconry raptors; and reptiles and amphibians. General practitioners are expected to stabilise, handle and treat them at a basic level and to know when to refer.
The subject is different from dog and cat medicine in three ways. First, most disease in these species is caused or allowed by the way the animal is kept: wrong temperature, wrong light, wrong diet, wrong substrate, wrong company. Second, many are small prey species that hide illness and can die from handling stress alone. Third, very few drugs are licensed for them, so the clinician works with extrapolated, off-label (extra-label) use under national prescribing rules.
This manual follows the curriculum units, and adds clinical examination and sampling sites, passerines, raptors, amphibians, and CITES in general terms. Free-living wildlife and zoo collections belong to the separate subject Wildlife and Zoo Medicine.
The NAVLE blueprint gives other small mammals about 3.3%, pet birds 2.3% and reptiles 1.5% of items; the South African Veterinary Council registration examination allots 10 marks of Paper 1 to exotic pets and cage birds; specialist colleges examine the field in depth. No drug dose in this manual is a recommendation: doses appear only in worked arithmetic, with the reminder to confirm against the product label and your national formulary.
Husbandry is the whole system by which an animal is kept: enclosure size and design, temperature, humidity, lighting, substrate, water, diet, cage-mates, hygiene and handling. In exotic pets most presenting problems are husbandry failures, either directly (a reptile with metabolic bone disease from a diet without calcium and a vivarium without ultraviolet light) or indirectly (a rabbit with dental disease from a diet low in abrasive fibre, which then stops eating and develops gut stasis). Treating the presenting sign without correcting the husbandry gives a short-lived improvement and a returning patient.
The husbandry history should therefore be taken before the physical examination, and in a structured way. Ask the exact species, age, sex and origin; enclosure size; heat source, thermostat and measured temperatures; lighting and the age of any ultraviolet lamp; humidity; substrate; water; diet in detail, including what is actually eaten and supplements; cage-mates; cleaning products; and recent changes. Photographs of the enclosure and a sample of the diet add information no question can.
Compare each answer with the species' natural history. A bearded dragon comes from arid, hot, bright Australian woodland and desert; a green iguana from humid tropical forest canopy and is a folivore (leaf eater); a chinchilla from cool, dry high Andes; a guinea pig from South American grassland and cannot make its own vitamin C.
Reptiles and amphibians are ectotherms: their body temperature, and therefore their metabolic rate, digestion, immune response and drug handling, depend on the temperature of their surroundings. Each species has a preferred optimum temperature zone (POTZ), the range within which it functions best, and a preferred body temperature that it seeks by moving between warm and cool areas. A vivarium must therefore offer a thermal gradient, with a basking site at the warm end and a cooler retreat, so that the animal can thermoregulate behaviourally. A single uniform temperature, however close to the mean of the POTZ, removes that choice. Temperatures must be measured, not guessed. Heat sources need thermostats and guards, because unguarded lamps and heat mats or so-called hot rocks cause severe thermal burns: reptiles do not move away from a burning surface as quickly as mammals do.
When a reptile is kept below its POTZ it eats less, digests poorly, becomes immunosuppressed and is predisposed to respiratory infection, stomatitis, gut stasis and parasitism. Hospitalised reptiles must be kept within their POTZ.
Many diurnal reptiles also need ultraviolet B (UVB) light, the band of roughly 290–315 nm that converts 7-dehydrocholesterol in the skin to previtamin D3. Without UVB, and without dietary vitamin D3, calcium cannot be absorbed from the gut. Glass and most plastics filter UVB, so a lamp behind glass or a sunny window gives the animal none. UVB output of lamps falls with use, so lamps are replaced on a schedule even when they still give visible light.
Rabbits, guinea pigs and chinchillas are hindgut fermenters that need a diet based on grass and hay. Long, abrasive fibre wears the continuously growing teeth through side-to-side chewing and keeps the gut moving. Diets high in concentrates, cereal mixes (muesli-type mixes from which the animal picks the sweet parts) and low in hay lead to acquired dental disease, obesity, gut stasis and caecal dysbiosis. Guinea pigs, like primates, lack the enzyme L-gulonolactone oxidase and cannot synthesise vitamin C, so they need a daily dietary source; vitamin C in pellets and drinking water degrades with time, light and heat.
Psittacine birds fed mainly on seed receive a diet high in fat and deficient in vitamin A, calcium, iodine and several amino acids. The results are hypovitaminosis A (squamous metaplasia of the oral, respiratory and urinary epithelium, predisposing to infection), obesity, hepatic lipidosis, lipomas in budgerigars, iodine-deficiency thyroid hyperplasia in budgerigars and hypocalcaemia, particularly in African grey parrots. Birds are converted gradually to a formulated (pelleted) diet with vegetables, monitoring weight.
Reptiles show the clearest nutrition-disease links. Insectivores fed only crickets or mealworms receive far more phosphorus than calcium, because invertebrates have an inverse calcium to phosphorus ratio; insects must be gut-loaded (fed a calcium-rich diet before being offered) and dusted with calcium. Combined with absent UVB, this produces nutritional secondary hyperparathyroidism, the main form of metabolic bone disease. Herbivorous reptiles such as green iguanas and tortoises fed animal protein develop gout and renal disease. Chelonians fed lettuce or meat develop hypovitaminosis A. Fish-eating snakes fed frozen fish containing thiaminase can develop thiamine deficiency.
Ferrets are obligate carnivores needing a high-protein, high-fat, low-fibre diet.
Handling exotic pets has two aims: the animal must not be hurt or frightened to the point of collapse, and the handler must not be bitten, scratched or exposed to zoonoses. Have everything ready before the animal leaves its carrier, and observe it at rest first. In birds and small prey mammals the hands-off observation is part of the examination: respiratory rate and effort, posture, alertness, droppings and gait are best seen undisturbed. A critically ill bird or small mammal may need oxygen and warmth before any handling.
Birds are caught in a darkened or dimmed room with a towel, the bird's head controlled from behind between the thumb and forefinger at the base of the skull and lower jaw (the mandible), keeping the beak away from the handler. The body and wings are wrapped in the towel. Birds have no diaphragm: they breathe by movement of the keel (sternum) and ribs, which moves air through the air sacs. Any grip that compresses the chest and coelom prevents breathing, and a bird can suffocate in a firm hand. Large parrots bite hard; raptors are dangerous mainly through their talons, so the feet are controlled first.
The avian examination starts with weight in grams, then covers eyes, nares, cere, beak, oral cavity and choana, crop, pectoral muscle over the keel (body condition), coelom, vent, feathers, feet and droppings. A dropping has three parts: faeces, white urates and clear urine. Green urates (biliverdinuria) suggest liver disease, including chlamydiosis. Birds are prey species that mask illness; the fluffed, sleepy bird on the cage floor, with tail bobbing as it breathes, is already seriously ill.
Rabbits have a light skeleton (bone is only a small fraction of body weight) and powerful hind limbs. If a rabbit kicks while its hindquarters are unsupported it can fracture or luxate its lumbar spine, the lumbosacral region being a classic site, and become paraplegic. Rabbits are therefore lifted with one hand under the chest and the other supporting the hindquarters, held close to the handler's body, and examined on a non-slip surface; wrapping in a towel helps for oral examination and sampling. Lifting by the ears is never acceptable.
Guinea pigs are lifted with one hand around the shoulders and the other under the hindquarters; pregnant sows especially need full support. Chinchillas are held at the base of the tail and around the body; rough handling or grabbing the coat causes fur slip, the release of patches of fur, which is a defence mechanism. Mice and rats may be held briefly at the base of the tail, never the tip. Gerbils and degus must never be held by the tail: the skin slips off (tail degloving). Hamsters are scooped in cupped hands; a hamster woken suddenly bites. Ferrets are held by the scruff with the hindquarters supported, which usually relaxes them.
The small mammal examination includes weight in grams, body condition, incisors and (with an otoscope) cheek teeth, eyes, chest, abdomen, skin, feet and the perineum, where pasted caecotrophs in a rabbit point to obesity, dental pain or dietary error.
Lizards are restrained with one hand around the pectoral girdle, controlling the forelimbs, and the other around the pelvis and hind limbs, keeping the tail against the handler's arm. Many lizards, including geckos and some skinks and iguanids, can shed the tail (caudal autotomy) through fracture planes in the vertebrae; the tail must never be used for restraint. Gentle pressure on the closed eyes of many lizards induces a vasovagal trance useful for radiography, not a substitute for anaesthesia.
Snakes are supported along their body, never allowed to hang from the head, and the head is controlled behind the jaws for large or aggressive snakes. Large constrictors should be handled by at least two people, and more for very large snakes. Venomous species need specialist equipment and trained staff.
Chelonians withdraw into the shell, and the head can be extracted by grasping behind the occipital region after waiting for the animal to extend it, or with gentle pressure on the hind limbs to push it forwards.
Amphibians, with their permeable skin, are handled minimally with moistened, powder-free gloves.
The reptile examination records weight and length, then checks eyes and spectacles, nares, mouth, skin and shed, cloaca, limbs, and in chelonians the shell.
Blood sampling in small patients is limited by volume. Birds have a blood volume in the region of 10% of body weight in many species, and a widely used conservative rule is to take no more than about 1% of body weight in millilitres from a healthy bird, less from a sick or anaemic one. Reptiles have a lower blood volume relative to body weight, and a commonly taught limit is a smaller fraction of body weight; texts differ, so use the figure in your formulary.
In birds the right jugular vein is the main site, because it is usually larger than the left, and it lies under an apterium (a featherless tract) on the right side of the neck. The basilic (ulnar) vein on the wing forms haematomas readily. The medial metatarsal (caudal tibial) vein is used in larger birds, waterfowl and raptors.
In lizards and snakes the ventral coccygeal (tail) vein is approached from the ventral midline, caudal to the cloaca, and in males caudal to the hemipenes. In chelonians the jugular vein gives the least lymph-contaminated sample; the subcarapacial sinus and the dorsal coccygeal vein are used, but lymphatics run close to them and lymph dilution can lower the packed cell volume and change cell counts. Lithium heparin is generally preferred over EDTA for reptile and some avian blood, because EDTA haemolyses the blood of chelonians and some bird species.
In rabbits the lateral saphenous and cephalic veins and the marginal ear vein are used; the central ear artery is for arterial samples and is avoided for injections. Ferrets: jugular vein or cranial vena cava under sedation. Rats and mice: lateral tail and lateral saphenous veins. Guinea pigs: lateral saphenous or cephalic for small volumes, cranial vena cava under anaesthesia for larger.
Exotic pets die under anaesthesia more often than dogs and cats, mostly from preventable causes: undetected disease, hypothermia, hypoventilation, airway obstruction and arithmetic overdose.
Before anaesthesia the animal is weighed in grams, examined, and stabilised: dehydration corrected, nutrition supported, and respiratory disease identified, since subclinical respiratory infection is common in rabbits and rats. Fasting rules differ. Rabbits and rodents cannot vomit, so a prolonged fast gives no protection against aspiration and harms gut motility and glucose balance; food is withheld only long enough to clear the mouth, which in guinea pigs and hamsters (cheek pouches) can still hold food. Ferrets can vomit and are fasted for a short period, usually a few hours, not longer, because of their short gut transit and the risk of hypoglycaemia in ferrets with insulinoma. Birds are fasted only long enough for the crop to empty, which is short in small birds with high metabolic rates; prolonged fasting causes hypoglycaemia. Reptiles are not fed for a period beforehand, depending on species and meal, to avoid regurgitation.
Small patients lose heat quickly; hypothermia slows drug metabolism and recovery. Warmed surfaces and fluids, minimal clipping, little alcohol on the skin and a warm recovery area are standard.
Monitor heart rate (stethoscope or Doppler), respiration, reflexes and temperature; pulse oximetry is less reliable in birds and reptiles. Monitoring continues until the animal is fully conscious and warm.
Birds have a unique respiratory system. The lungs are small, rigid and do not expand; air flows in one direction through parabronchi, driven by bellows-like air sacs (nine in most psittacines). There is no diaphragm, and both inspiration and expiration are active, produced by movements of the keel and ribs. When a bird is placed in dorsal recumbency, the weight of the viscera on the air sacs reduces ventilation, and under anaesthesia the respiratory muscles are depressed, so hypoventilation and apnoea are common. Intermittent positive pressure ventilation is used routinely.
Inhalational agents (isoflurane, sevoflurane) are preferred for most pet birds because induction and recovery are fast and the depth is easily changed; induction is by face mask while the bird is held in a towel. Birds have complete tracheal rings, so tracheal tubes are either uncuffed or the cuff is not inflated, because pressure on the rings can cause tracheal mucosal necrosis and later stricture. The glottis lies at the base of the tongue and is easily seen. In birds with upper airway obstruction, such as a tracheal granuloma from aspergillosis, an air sac breathing tube placed into the caudal thoracic or abdominal air sac allows ventilation and anaesthesia through the air sac.
Changes in anaesthetic depth are rapid, and apnoea can progress quickly to cardiac arrest. Heart rate is monitored with a Doppler probe over the ulnar or medial metatarsal artery or on the cornea, and respiration and temperature continuously.
Reptiles can hold their breath and switch to anaerobic metabolism for long periods, chelonians and aquatic species most of all, so induction with an inhalational agent by mask or chamber is slow and unreliable. Induction is usually injectable, intravenous or intraosseous where access allows, or intramuscular, followed by intubation and maintenance with an inhalational agent. The glottis of lizards and snakes lies far forward at the base of the tongue and is easy to intubate; chelonians have complete tracheal rings and a short trachea that divides into the bronchi high in the neck, so a short tube is used to avoid intubating one bronchus. Reptiles generally do not breathe adequately under anaesthesia and need intermittent positive pressure ventilation at a low rate.
Many reptiles and birds have a renal portal system, in which blood from the caudal body and hind limbs can pass through the kidneys before reaching the systemic circulation. Its clinical importance for injected drugs is debated, but many clinicians give injections in the cranial half of the body, especially for nephrotoxic drugs or drugs excreted by the kidneys.
In reptiles the drive to breathe is stimulated more by low oxygen than by high carbon dioxide. Many texts therefore advise ventilating with room air rather than pure oxygen during recovery, so that the animal resumes spontaneous breathing sooner; this view is widely taught but not universally accepted. Recovery is slow, sometimes hours, and the reptile must be kept within its POTZ until it is fully mobile.
Amphibians and many fish are anaesthetised by immersion in water containing a buffered solution of tricaine methanesulfonate, since the drug is absorbed through the skin and gills; unbuffered solution is acidic and irritant.
Rabbits are difficult to intubate. The oropharynx is long and narrow, the tongue is large, the incisors restrict opening and the glottis is small and hard to see, and laryngospasm can follow clumsy attempts. Methods include intubation under direct vision with an endoscope or laryngoscope, blind intubation guided by breath sounds, and rabbit-specific supraglottic airway devices. Rabbits that are masked with isoflurane often breath-hold because the agent is aversive, leading to hypoxia and bradycardia; premedication and preoxygenation reduce this. Postoperative analgesia and early eating prevent gut stasis.
Guinea pigs and chinchillas are also hard to intubate (the guinea pig has a palatal ostium, an opening in the soft palate continuous with the tongue), so many procedures are done with a mask. Ferrets are intubated as easily as cats.
Small mammals have high metabolic rates and doses per kilogram are often higher than for dogs; doses scale more closely with metabolic body size (body weight raised to the power 0.75) than with weight alone. Allometric scaling uses this to extrapolate doses between species, but ignores species differences in metabolism.
Analgesia is part of anaesthesia. Prey species hide pain, so pain scoring uses behaviour (posture, hunching, reduced grooming, teeth grinding in rabbits) and validated grimace scales exist for rabbits, rats and mice. Non-steroidal anti-inflammatory drugs and opioids are used across taxa, but responses to opioids differ markedly between species; total local anaesthetic doses must be calculated because toxic doses are reached with very small volumes.
The commonest fatal drug error in exotic patients is a slip between grams and kilograms. The steps are always: convert the body weight to kilograms; multiply by the dose rate in mg/kg to get the dose in mg; divide by the concentration in mg/mL to get the volume in mL; and check that the volume is physically measurable.
Worked example. A 450 g parrot is to receive a drug at 1 mg/kg from a 1.5 mg/mL solution. Weight = 0.45 kg. Dose = 1 × 0.45 = 0.45 mg. Volume = 0.45 ÷ 1.5 = 0.3 mL. Dose figures are for illustration of the arithmetic only — confirm against the product label and your national formulary.
When the volume is too small to measure accurately (a common problem in budgerigars and mice), the drug is diluted with a compatible diluent. A 30 g budgerigar needing 10 mg/kg of a 100 mg/mL drug needs 0.3 mg, which is 0.003 mL of stock solution, impossible to draw up. Diluting the stock 1 in 10 gives 10 mg/mL, and the volume becomes 0.03 mL, which can be measured with an insulin syringe. Dose figures are for illustration of the arithmetic only — confirm against the product label and your national formulary. Check that the product can be diluted.
The same arithmetic applies to fluids. Maintenance fluid rates are given per kilogram per day in formularies and vary between taxa and texts, and a deficit is added: deficit (mL) = body weight (g) × percentage dehydration as a decimal, since 1 g of water is about 1 mL. For a 1.2 kg ferret estimated 5% dehydrated, the deficit is 1200 × 0.05 = 60 mL, to be added to maintenance and replaced over a chosen period. In birds the intraosseous route uses the distal ulna or proximal tibiotarsus (never the pneumatised humerus or femur, which communicate with air sacs).
The domestic rabbit (Oryctolagus cuniculus) is a lagomorph, not a rodent: it has a second, small pair of upper incisors (peg teeth) behind the first. Its dental formula is I 2/1, C 0/0, P 3/2, M 3/3, giving 28 teeth, and all of them are elodont (open-rooted and continuously growing throughout life) and, for the cheek teeth, hypsodont (long-crowned). Normal wear depends on long periods of side-to-side chewing of abrasive grass and hay.
The rabbit is a hindgut fermenter. Large indigestible fibre particles move quickly through the colon and are passed as hard faecal pellets; small particles and fluid are moved back into the large caecum, where bacteria ferment them. The caecal contents are periodically expelled as caecotrophs, soft, mucus-covered pellets rich in protein and B vitamins, which the rabbit eats directly from the anus (caecotrophy).
Gastrointestinal stasis (ileus) is reduced or absent gut motility, and it is one of the commonest emergencies in pet rabbits. It is usually secondary: to dental pain, a low-fibre diet, stress, pain from any cause, other illness or anaesthesia. Signs are reduced or absent eating and faecal output, small or no droppings, hunching and teeth grinding (bruxism). Hair in the stomach is a consequence of stasis, not usually its cause. Treatment is analgesia, fluids, warmth, assisted feeding and prokinetics once obstruction is excluded, plus treatment of the cause.
Gastrointestinal obstruction, often of the proximal small intestine by a compacted pellet of hair or foreign material, must be distinguished from stasis because prokinetics are contraindicated and surgery may be required. Obstruction typically presents acutely with severe pain, depression and a palpably distended, fluid- and gas-filled stomach, sometimes with shock, and radiographs show gastric distension with gas proximal to the obstruction. Blood glucose is often markedly raised in obstruction, and serial measurement helps to distinguish it from simple stasis.
Acquired dental disease is extremely common in pet rabbits and is mainly attributed to a diet that is too low in long fibre to allow normal wear. As cheek teeth elongate, sharp spurs form on the lingual (tongue) side of the mandibular cheek teeth and the buccal (cheek) side of the maxillary cheek teeth, lacerating the tongue and cheeks. The tooth roots also elongate (retrograde growth), penetrating the ventral cortex of the mandible as palpable swellings, or growing towards the orbit and the nasolacrimal duct. Signs include dropping food, drooling, epiphora from blocked nasolacrimal ducts, facial abscesses and secondary gut stasis.
Incisor malocclusion may be congenital, most often from relative mandibular prognathism (a short upper jaw) in dwarf and lop breeds, or acquired secondary to cheek-teeth disease. Clipping incisors with nail clippers splits the teeth and is condemned; incisors are trimmed with a dental burr, or extracted when malocclusion is permanent.
Diagnosis needs oral examination under anaesthesia and skull radiography or CT. Treatment is correction of crowns under anaesthesia with dental burrs, extraction of diseased teeth, management of abscesses (which in rabbits contain thick caseous pus and a fibrous capsule, so they are usually removed surgically or marsupialised rather than simply lanced), and permanent dietary change.
Encephalitozoon cuniculi is a microsporidian parasite spread by spores in urine, by ingestion and transplacentally. Clinical disease takes three main forms: neurological (vestibular signs with head tilt, rolling, nystagmus, and sometimes paresis), ocular (phacoclastic uveitis, in which the lens capsule ruptures, often in young rabbits infected in utero, giving a white mass in the eye) and renal (chronic interstitial nephritis). Seropositivity shows exposure, not disease, so diagnosis combines signs, serology and exclusion of other causes, particularly otitis media and interna from bacterial infection, which also causes head tilt. Benzimidazole treatment (fenbendazole is the drug most often used, for weeks rather than days) is given with supportive care.
Pasteurella multocida causes rhinitis (snuffles), otitis, pneumonia and abscesses, and is often carried subclinically.
Myxomatosis is caused by a leporipoxvirus spread mainly by biting arthropods, especially rabbit fleas and mosquitoes. Classical signs are swelling of the eyelids, face, ears and anogenital region; nodular and atypical respiratory forms occur. Rabbit haemorrhagic disease is caused by lagoviruses (caliciviruses). The classical virus (RHDV1) kills adult rabbits peracutely, with young kits under about eight weeks largely resistant; the variant RHDV2, which spread from 2010, also kills young rabbits and has a longer course. Vaccines against myxomatosis and RHD exist, but which are authorised varies by country.
Flystrike (myiasis) in rabbits with faecal soiling is an emergency. Rabbit syphilis (Treponema paraluiscuniculi) causes genital and facial crusts.
Uterine adenocarcinoma is the commonest tumour of intact female rabbits and becomes frequent from middle age; it metastasises to the lungs, so thoracic radiographs precede surgery, and elective ovariohysterectomy of does prevents it. Rabbits absorb calcium from the gut largely in proportion to the amount in the diet and excrete the excess in urine, so normal rabbit urine is often cloudy; excess dietary calcium, obesity, inactivity and low water intake predispose to urinary sludge and urolithiasis.
Antibiotic choice is critical: oral lincosamides (clindamycin, lincomycin), oral penicillins such as amoxicillin and ampicillin, oral cephalosporins and some macrolides can disrupt the caecal flora and cause fatal enterotoxaemia from Clostridium spiroforme overgrowth. The ectoparasiticide fipronil is contraindicated in rabbits.
Guinea pigs (Cavia porcellus) and chinchillas (Chinchilla lanigera) are hystricomorph rodents. Unlike rats, mice and hamsters, in which only the incisors grow continuously, all their teeth (incisors and cheek teeth) are elodont, so they suffer acquired dental disease as rabbits do. In guinea pigs the mandibular cheek teeth tend to overgrow towards the tongue and can trap it (tongue entrapment), and the animal starves despite apparent interest in food. The guinea pig dental formula is I 1/1, C 0/0, P 1/1, M 3/3, giving 20 teeth.
Guinea pigs need dietary vitamin C. Deficiency (scurvy) causes reluctance to move, swollen painful joints, haemorrhages in joints, gums and muscle, poor wound healing, weight loss, loosened teeth and secondary infections. A daily dietary source is essential, and needs rise in pregnancy and illness.
Female guinea pigs that are bred for the first time after the pubic symphysis has fused, which texts place at around six months of age, risk dystocia because the symphysis no longer separates. Cystic ovaries (cysts of the rete ovarii) are very common in older sows, sometimes with bilaterally symmetrical flank alopecia. Other common conditions include bacterial pneumonia (Bordetella bronchiseptica, which rabbits can carry without signs, and Streptococcus species), urolithiasis, and the sarcoptic mite Trixacarus caviae, which causes intense pruritus, alopecia and, in severe cases, seizure-like episodes. Dermatophytosis (Trichophyton species) is zoonotic.
Chinchillas come from cold, dry mountains and are very susceptible to heat stroke; they need a cool, dry, well-ventilated room and dust baths to keep the dense coat in condition. Dental disease and fur chewing are common. Degus (Octodon degus) are prone to diabetes mellitus and cataracts and should not be fed sugary foods.
Rats (Rattus norvegicus) and mice (Mus musculus) are myomorph rodents with continuously growing incisors and rooted cheek teeth (dental formula I 1/1, C 0/0, P 0/0, M 3/3, 16 teeth). Incisor malocclusion is the main dental problem; the normal yellow-orange enamel of the incisors is not a sign of disease.
Respiratory disease is the leading cause of illness in pet rats. Murine respiratory mycoplasmosis, caused by Mycoplasma pulmonis, often with other bacteria and viruses, presents with sneezing, snuffling, head tilt from otitis media, and chronic bronchopneumonia with bronchiectasis. It is worsened by ammonia from dirty bedding and dusty substrates. It is managed but rarely cured. Red-brown staining around the eyes and nose (chromodacryorrhoea) is porphyrin pigment from the Harderian gland, behind the eye, and is a non-specific sign of stress or illness, not blood.
Mammary tumours are very common in female rats and are usually benign fibroadenomas, which can grow very large; in mice mammary tumours are more often malignant adenocarcinomas. Pituitary adenomas are common in older rats and cause neurological signs. Chronic progressive nephropathy is common in ageing rats.
Mice show barbering (a dominant mouse chewing cage-mates' whiskers) and males fight.
Syrian hamsters (Mesocricetus auratus) are solitary as adults and fight if housed together; dwarf hamsters (Phodopus and Cricetulus species) are more social. Hamsters have large cheek pouches that can become impacted or everted. Proliferative ileitis (wet tail), caused by Lawsonia intracellularis, affects young, recently weaned hamsters with watery diarrhoea, a wet perineum and a high mortality. Hamsters are highly susceptible to antibiotic-associated enterotoxaemia. Demodicosis (Demodex criceti and D. aurati) in older hamsters is often linked to underlying disease. Diabetes mellitus occurs in Chinese and Campbell's dwarf hamsters.
Gerbils (Meriones unguiculatus) come from arid regions and need little water. They suffer tail degloving if held by the tail, inherited epileptiform seizures often triggered by handling or a new environment, and nasal dermatitis (sore nose) linked to Harderian gland secretions and burrowing. Tyzzer's disease, caused by Clostridium piliforme, is a severe enteric and hepatic infection of gerbils and other rodents. Cystic ovaries and tumours of the ventral scent gland occur in older gerbils.
All rodents need species-appropriate company, deep dust-free bedding, gnawing material and good ventilation.
The domestic ferret (Mustela putorius furo) is a mustelid carnivore. Its gut is short, without a caecum, and food passes through in a few hours, so it eats small meals often and needs a diet high in animal protein and fat and low in fibre and simple carbohydrates. Ferrets have a dental formula of I 3/3, C 1/1, P 3/3, M 1/2, giving 34 teeth. Males are called hobs, females jills and young kits. Jills are induced ovulators and seasonal breeders: in the breeding season an unmated jill can remain in oestrus for a long period.
Young ferrets swallow rubber and foam foreign bodies. Splenomegaly is a common incidental finding in older ferrets, often from extramedullary haematopoiesis, but may also be caused by lymphoma or other disease, so it needs evaluation in a sick ferret.
Vaccination against canine distemper is essential where the disease occurs, because distemper in ferrets is almost always fatal. Rabies vaccination is required or recommended in many countries. Ferrets are susceptible to heartworm (Dirofilaria immitis) where it is endemic, and a very small worm burden can kill because the heart is small, so prevention is advised in those regions. Ferrets catch human influenza A and can pass it back.
Adrenocortical disease, often called hyperadrenocorticism, is one of the most common diseases of middle-aged pet ferrets, particularly where ferrets are neutered at a young age. Unlike canine Cushing's disease, the adrenal glands of affected ferrets produce excess sex steroids (oestradiol, androstenedione and 17-hydroxyprogesterone) rather than cortisol. The lesion is adrenal hyperplasia, adenoma or adenocarcinoma. The leading explanation is that after neutering, the loss of gonadal negative feedback leaves gonadotrophins (luteinising hormone) persistently high, and adrenal cells with LH receptors are stimulated.
Signs are bilaterally symmetrical alopecia that usually begins at the tail and spreads forwards, sometimes with pruritus; vulvar swelling in a spayed jill; and in hobs, prostatic enlargement and cysts that can obstruct urination, a true emergency. Diagnosis is by signs, adrenal ultrasonography and, where available, an adrenal steroid panel.
Treatment is either medical, with a GnRH agonist implant (deslorelin) or depot injection (leuprolide) that suppresses gonadotrophin release, or surgical adrenalectomy. The left adrenal is relatively easy to remove; the right adrenal is closely attached to, and sometimes invades, the caudal vena cava, making its removal more difficult.
Insulinoma, a functional tumour of the pancreatic beta cells, is the most common tumour of middle-aged and older ferrets. Excess insulin causes hypoglycaemia, with episodes of lethargy, weakness of the hind limbs, ptyalism (drooling), pawing at the mouth, a glazed look, collapse and seizures, often after a period without food or after exercise. Diagnosis is by demonstrating fasting hypoglycaemia under supervision, ideally with a concurrent normal or high insulin concentration; a ferret should not be fasted for long, and should be watched while fasted. Blood glucose may be reported in mmol/L or mg/dL; the conversion factor is about 18 (mg/dL = mmol/L × 18). Treatment is surgical removal of nodules (partial pancreatectomy), which is rarely curative because microscopic metastasis is common, or medical management with frequent high-protein meals, glucocorticoids (prednisolone) and diazoxide. An emergency hypoglycaemic crisis is treated with glucose, given carefully because a bolus can stimulate the tumour to release more insulin.
Lymphoma occurs as a juvenile form, often mediastinal, and an adult multicentric form.
Hyperoestrogenism affects intact jills that remain in oestrus without being mated. Persistently high oestrogen suppresses the bone marrow, causing aplastic anaemia, thrombocytopenia with petechiae and haemorrhage, leukopenia and secondary infections; it can be fatal. Prevention is spaying, a GnRH agonist implant, hCG or GnRH injection to induce ovulation, or a vasectomised hob. A jill already severely anaemic may need blood transfusion before surgery; ferrets are reported to lack clinically significant blood groups, so a first transfusion carries little risk of reaction.
Other ferret diseases include Helicobacter mustelae gastritis and gastric ulcers, epizootic catarrhal enteritis caused by a ferret enteric coronavirus (green, mucoid diarrhoea), ferret systemic coronavirus disease (a pyogranulomatous condition resembling feline infectious peritonitis), Aleutian disease (a parvovirus causing hypergammaglobulinaemia and immune-complex disease) and cardiomyopathy.
Pet birds include psittacines (parrots, from budgerigars and cockatiels to African grey parrots, Amazons, cockatoos and macaws), passerines (canaries, finches) and, for falconers, raptors (falcons, hawks, owls). Their shared biology shapes clinical practice. Small birds starve quickly; a bird not eating for a day or two is an emergency. Their respiratory system of fixed lungs and air sacs makes them sensitive to airborne toxins, which is why fumes from overheated polytetrafluoroethylene (PTFE) non-stick cookware can kill pet birds within minutes through acute pulmonary haemorrhage and oedema, and why aerosols, smoke and scented products are hazardous.
Birds are uricotelic: the main nitrogenous waste is uric acid, excreted as urates. Dehydration, renal disease and high-protein diets can cause gout, with urate deposits in joints (articular gout) or on serosal surfaces of viscera (visceral gout). The stomach has a glandular proventriculus and a muscular ventriculus (gizzard); owls lack a true crop.
Many psittacines are sexually monomorphic, so sex is determined by DNA testing of feathers or blood, or by endoscopy; adult budgerigars of the normal colour are the familiar exception, with a blue cere in males and a brown cere in females. A change of cere colour in a male budgerigar towards brown can indicate a testicular tumour (Sertoli cell tumour with oestrogen production).
Seed-based diets cause most of the nutritional disease seen in pet psittacines. Hypovitaminosis A leads to squamous metaplasia of mucous membranes: blunted choanal papillae, white plaques or abscesses in the mouth and sinuses, sinusitis, and poor feather quality. Obesity, hepatic lipidosis (fatty liver) and lipomas are common in budgerigars, cockatiels, Amazons and galahs. Budgerigars fed seed from iodine-deficient areas develop thyroid hyperplasia (goitre), which compresses the syrinx, trachea and oesophagus and causes voice change, clicking respiratory sounds and regurgitation. African grey parrots are prone to hypocalcaemia with seizures. Overgrowth of the beak in budgerigars often reflects liver disease rather than simple wear failure.
Heavy-metal poisoning is common in birds that chew. Lead comes from old paint, curtain weights, solder and fishing weights; zinc from galvanised cage wire and fittings (new wire disease). Signs include regurgitation, polyuria, haemoglobinuria (lead, especially in Amazons) and neurological signs. Radiographs may show radiodense particles in the ventriculus, and blood lead or zinc confirms. Treatment is chelation (calcium disodium EDTA, or oral agents) with removal of the particles. Avocado and chocolate are also toxic.
Chronic egg laying is common in cockatiels, budgerigars and lovebirds, especially single hand-reared birds bonded to their owner, and depletes calcium. Egg binding (dystocia) presents as straining, a wide stance, depression and a palpable egg; treatment is warmth, humidity, fluids and calcium, then manual delivery, ovocentesis or surgery.
Feather-damaging behaviour, in which a bird plucks or chews its own feathers, is common in African greys and cockatoos. It is multifactorial: medical causes must be excluded before blaming behaviour and husbandry.
Renal adenocarcinoma in budgerigars compresses the ischiatic nerve and causes unilateral lameness or paralysis of a leg.
Psittacine beak and feather disease (PBFD) is caused by a circovirus (beak and feather disease virus). The chronic form causes progressive dystrophic feathers (pinched, clubbed, haemorrhagic, curled) and, in some species, beak overgrowth and necrosis, especially in cockatoos; the acute form kills young birds. It is immunosuppressive. Diagnosis is by PCR of blood or feather; there is no specific treatment, and control relies on testing and isolation.
Avian polyomavirus causes budgerigar fledgling disease (abnormal feathering, death in nestlings) and acute death with haemorrhages in young larger psittacines such as macaws and conures. Proventricular dilatation disease, caused by parrot bornavirus, is a ganglioneuritis that impairs gut motility, causing weight loss, regurgitation, undigested seed in the droppings and neurological signs; contrast radiography shows a dilated proventriculus.
Aspergillosis, usually from Aspergillus fumigatus, is a fungal infection of the air sacs, lungs and syrinx acquired by inhaling spores from mouldy substrate or food. Predisposing factors are immunosuppression, stress, poor ventilation and hypovitaminosis A. African greys, Amazons and raptors (gyrfalcons, goshawks) and other birds are susceptible. Signs are exercise intolerance, dyspnoea and a change or loss of voice when the syrinx is involved. Diagnosis is by radiography, endoscopy and culture; treatment is long-term antifungals.
Chlamydiosis (psittacosis) is described in the zoonoses chapter. Macrorhabdus ornithogaster (avian gastric yeast) causes chronic wasting and regurgitation in budgerigars. Knemidocoptes mites cause honeycomb-like crusts on the cere, beak and legs of budgerigars. Trichomonas gallinae causes caseous lesions in the oropharynx and crop of pigeons and budgerigars, and in raptors that eat pigeons (frounce).
Passerines: canaries are affected by canary pox (an avipoxvirus with high mortality in its systemic form), air sac mites (Sternostoma tracheacolum) causing clicking breathing and voice loss in canaries and Gouldian finches. Raptors: bumblefoot (pododermatitis), linked to poor perches, overweight and inactivity, aspergillosis, frounce, and lead poisoning from shot in prey.
Many pet birds and reptiles are traded internationally, and their trade is regulated by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). In general terms, Appendix I lists species threatened with extinction, for which commercial trade in wild-caught specimens is essentially prohibited and trade is permitted only in exceptional circumstances with both export and import permits; Appendix II lists species not necessarily threatened but whose trade must be controlled to avoid use incompatible with their survival, requiring export permits; and Appendix III lists species protected in at least one country that has asked other parties for help in controlling trade. Captive-bred specimens of Appendix I species can in some circumstances be traded under specific provisions.
Nearly all parrots are listed in Appendix II or Appendix I; the budgerigar, cockatiel, rose-ringed parakeet and peach-faced lovebird are among the few psittacines excluded from the appendices. The African grey parrot was moved from Appendix II to Appendix I by the CITES Conference of the Parties in 2016 because of trade-driven population declines.
National and regional laws add their own controls: the European Union applies stricter annexes through its wildlife trade regulations; the United States has the Endangered Species Act and the Lacey Act; India's Wild Life (Protection) Act prohibits keeping many native birds, including native parakeets, as pets, regardless of CITES status. Treating an animal does not legalise its possession.
Reptiles are ectotherms with low metabolic rates, so disease progresses slowly and response to treatment is slow; a reptile may have been ill for weeks before it is presented. Most have a three-chambered heart and no diaphragm; terrestrial species excrete uric acid, so dehydration leads to gout. Squamates (lizards and snakes) have paired hemipenes in the male, stored in pockets in the tail base; chelonians and crocodilians have a single phallus. Snakes are sexed by probing the hemipenal pockets, which are deeper in males. Snakes and many geckos have a transparent spectacle over each eye, shed with the skin.
Nutritional secondary hyperparathyroidism (NSHP) is the most important form of metabolic bone disease (MBD) in captive reptiles. A diet low in calcium or with an inverse calcium to phosphorus ratio, and a lack of vitamin D3 from UVB light or diet, lower blood calcium; parathyroid hormone rises and mobilises calcium from bone, which is replaced by fibrous tissue (fibrous osteodystrophy). It is seen in young, fast-growing insectivorous and herbivorous lizards (bearded dragons, green iguanas, chameleons, leopard geckos) and in chelonians. Signs are a soft, rubbery mandible, swollen limbs (the swelling is fibrous tissue, not muscle), pathological fractures, spinal deformity, a soft shell and pyramiding in chelonians, inability to lift the body, and tremors, muscle fasciculations and tetany from hypocalcaemia. Radiographs show reduced bone density, thin cortices and folding fractures. Treatment is calcium, UVB, diet correction and careful handling. Renal secondary hyperparathyroidism, from kidney disease, is a different condition with a high blood phosphorus.
Other husbandry diseases of reptiles include dysecdysis (incomplete shedding, often with retained spectacles in snakes, from low humidity or illness), thermal burns, rodent bite injuries when live prey is left in a vivarium, hypovitaminosis A in chelonians, gout and renal disease in herbivores fed animal protein or kept dehydrated, obesity and hepatic lipidosis.
Chelonians: hypovitaminosis A in box turtles and terrapins fed unbalanced diets causes swollen eyelids (blepharoedema), aural abscesses (swelling of the tympanic scale), respiratory infection and skin changes; injected vitamin A is given cautiously because overdose causes skin sloughing. Post-hibernation anorexia in tortoises follows hibernation in poor condition, at the wrong temperature or for too long, and tortoises should be health-checked before hibernation. Testudinid herpesviruses cause stomatitis with diphtheritic plaques and rhinitis, and Mycoplasma species cause upper respiratory tract disease. Ivermectin is toxic to chelonians and is not used in them.
Snakes: inclusion body disease, caused by reptarenaviruses, affects boas and pythons, with regurgitation, wasting and neurological signs such as head tremor, disorientation and stargazing; boas may carry infection for long periods, while pythons usually develop more severe neurological disease. Diagnosis is by inclusion bodies in blood cells or biopsies, and PCR. The snake mite (Ophionyssus natricis) causes anaemia and dysecdysis and can carry pathogens. Cryptosporidium serpentis infects the gastric mucosa, causing hypertrophic gastritis, mid-body swelling and chronic regurgitation; there is no reliable cure and affected snakes are isolated or euthanased. Stomatitis, respiratory infection (often secondary to cold) and ferlavirus infection also occur.
Lizards: in addition to NSHP, bearded dragons suffer adenovirus infection and the yellow fungus disease caused by Nannizziopsis species (formerly called the Chrysosporium anamorph of Nannizziopsis vriesii), a contagious and often fatal dermatomycosis. Leopard geckos suffer cryptosporidiosis (Cryptosporidium varanii), causing wasting with a thin tail.
Reproductive disease: female lizards and chelonians can suffer preovulatory follicular stasis, in which follicles develop but are not ovulated and remain in the ovary, and postovulatory egg retention (dystocia). Follicular stasis is treated by ovariectomy; egg retention by nesting conditions, calcium, or surgery. Prolapse through the cloaca may involve the cloaca, colon, oviduct, hemipenis or phallus, or the bladder in chelonians; identifying the tissue determines treatment, and a prolapsed hemipenis that is necrotic can be amputated because it is not used for urination.
Amphibians have a thin, permeable, glandular skin through which they absorb water and oxygen and lose electrolytes, so water quality is central to their health. Tap water is treated to remove chlorine and chloramine; ammonia and nitrite from waste must be kept low by filtration and water changes; temperature must suit the species.
Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), infects the keratinised skin, causing excessive skin shedding, disturbance of electrolyte transport across the skin (with low sodium and potassium in the blood) and death from cardiac arrest. It has driven amphibian declines and extinctions worldwide. Batrachochytrium salamandrivorans (Bsal) causes ulcerative skin disease in salamanders and newts. Diagnosis is by PCR on skin swabs. Ranaviruses (iridoviruses) cause systemic haemorrhagic disease and mass mortality. Infection with Bd, Bsal and ranavirus are listed by the World Organisation for Animal Health (WOAH). Red-leg syndrome is a septicaemia with reddening of the ventral skin and legs caused by Aeromonas hydrophila and other bacteria, usually secondary to poor water quality and stress.
Amphibians are handled with moistened, powder-free gloves, and drugs are often given by immersion (bath) or topically because of skin absorption. Anaesthesia is usually by immersion in buffered tricaine methanesulfonate.
Many reptile species are listed under CITES, including many tortoises, monitor lizards, chameleons, boas and pythons. Captive-bred animals avoid the conservation and disease risks of wild collection. Some jurisdictions license or forbid keeping large constrictors, venomous species or native species.
Euthanasia of reptiles needs particular care because the reptilian brain tolerates hypoxia and low perfusion, and a reptile can appear dead while still conscious. Guidelines from veterinary bodies recommend a two-step approach: deep anaesthesia or an injectable euthanasia agent, followed, where the animal is not confirmed dead, by physical destruction of the brain; confirmation of death by Doppler is more reliable than auscultation. Freezing a conscious reptile is not humane and is not an acceptable method.
Psittacosis is human infection with Chlamydia psittaci (formerly Chlamydophila psittaci), an obligate intracellular bacterium. In birds the disease is called avian chlamydiosis; it occurs in psittacines, pigeons, poultry (ducks and turkeys especially) and many wild birds. The elementary body, shed in faeces and secretions, survives long in dried droppings and dust. Many birds carry the organism without signs and shed it intermittently; shedding increases with stress such as shipping, crowding, breeding and illness, which is why newly purchased birds and birds in shops and aviaries are a common source.
Typical signs are lethargy, conjunctivitis, nasal discharge, dyspnoea, diarrhoea and green urates (biliverdinuria) from liver involvement; the liver and spleen are often enlarged on radiographs. PCR on choanal, conjunctival and cloacal swabs detects shedding, but a single negative does not rule out infection; serology shows exposure; combining and repeating tests improves accuracy.
Treatment of birds is long-course tetracycline therapy, usually doxycycline; national guidance, such as the compendium published by the National Association of State Public Health Veterinarians in the United States, has traditionally recommended a 45-day course, with retesting after treatment.
In people, infection is mainly by inhaling aerosolised dried droppings or feather dust; brief exposure can be enough, and some patients cannot recall bird contact. Disease ranges from flu-like illness to atypical pneumonia and is treated with tetracyclines. Psittacosis is notifiable or reportable in many countries, though not all; check the national list.
Prevention: buy birds from tested sources, quarantine and test new birds before introducing them, clean cages daily, wet droppings with disinfectant before removing them to avoid raising dust, wear a fitted particulate respirator and gloves when cleaning heavily contaminated areas or handling suspect birds, and tell owners to mention bird contact to their doctor if they develop respiratory illness.
Salmonella enterica is carried in the intestinal tract of a large proportion of healthy reptiles, including lizards, snakes and chelonians; amphibians, pet rodents, hedgehogs and backyard poultry also carry it. Reptiles carry many serovars, including subspecies rarely found in mammals (for example S. enterica subspecies arizonae and diarizonae in snakes). Carriage is usually asymptomatic and shedding is intermittent, so a negative faecal culture does not show that a reptile is free of Salmonella. Treating reptiles with antibiotics to eliminate carriage is not recommended: it rarely succeeds and promotes resistance.
Human infection is by the faecal-oral route, directly from handling the animal or indirectly from contaminated surfaces, water, enclosures and food preparation areas. Reptile-associated salmonellosis is more severe in children under five years, older people, pregnant women and immunocompromised people, in whom septicaemia, meningitis and death occur. Outbreaks have been linked to small turtles, bearded dragons, frozen feeder rodents, African dwarf frogs and hedgehogs. In the United States the sale of turtles with a carapace shorter than 4 inches (about 10 cm) has been prohibited since 1975, because small turtles were handled and mouthed by young children.
Advice given in public health guidance in several countries: wash hands thoroughly with soap and water after handling reptiles, amphibians, their food, water or enclosures; do not let reptiles roam freely in kitchens or food areas; do not clean enclosures or bowls in the kitchen sink or bathtub; supervise children's hand washing; and keep reptiles and amphibians out of households with children under five, pregnant women or immunocompromised people, and out of settings such as nurseries and childcare centres. Give this advice at the first visit.
Lymphocytic choriomeningitis virus (LCMV), an arenavirus carried by house mice and pet hamsters, causes a flu-like illness or meningitis in people and can cause severe birth defects or fetal death when a pregnant woman is infected; infected rodents often show no signs. Rat-bite fever is caused by Streptobacillus moniliformis (and Spirillum minus in Asia), carried in the oral and nasal flora of healthy rats, and causes fever, rash and polyarthritis after a bite or scratch. Trichophyton ringworm passes from guinea pigs and rabbits. Cheyletiella parasitovorax (walking dandruff) of rabbits causes itchy papules in people. Pasteurella multocida is common in bite wounds from rabbits and ferrets. Ferrets transmit influenza A both ways and must be vaccinated against rabies where rabies occurs.
General measures: hand hygiene, gloves and masks where aerosols or bites are likely, quarantine of new animals, wound care, and protecting high-risk people.
As a student your tasks are to handle exotic pets safely and to recognise the classic husbandry diseases. Practise taking a full husbandry history and checking it against each species' natural history. Learn the restraint rules that prevent harm (support the rabbit's hindquarters, never compress a bird's chest, never hold a gerbil's tail or a lizard's tail), the blood sampling sites by taxon, and the safe blood-volume rule for birds. Know the dental formulas and which teeth grow continuously in rabbits, hystricomorph and myomorph rodents. Memorise the high-yield disease links: seed diet and hypovitaminosis A, missing UVB and NSHP, guinea pigs and vitamin C, ferret adrenal disease and insulinoma, unmated jills and aplastic anaemia, oral lincosamides and rabbit enterotoxaemia, and the zoonoses psittacosis and Salmonella.
Five years into practice you are the person who sees the rabbit in gut stasis on a Sunday and the egg-bound cockatiel at closing time. You decide quickly whether a stasis rabbit has an obstruction (pain, distended stomach, high glucose, radiographs) and needs surgery or referral. You run safe anaesthesia for dental procedures, rabbit spays and ferret adrenal or insulinoma surgery: short fasts, warming, airway control, ventilation in birds and reptiles, and drug volumes calculated from weight in grams and diluted when needed. You convert bird owners to formulated diets, fix vivarium lighting and temperature, advise on vaccination of rabbits and ferrets under your country's authorised products, and counsel every reptile and bird owner on Salmonella and psittacosis, including whether the household includes high-risk people.
With twenty-five years' experience you set the standard for exotic care in a practice or group. You write protocols for anaesthesia, analgesia and fluid therapy by taxon, hospital housing with species-specific temperature and humidity, and safe isolation of birds suspected of chlamydiosis. You train staff in restraint and sampling, audit anaesthetic deaths, and decide which cases stay in-house and which go to a specialist. You handle the legal side: off-label prescribing under the national framework, record-keeping, CITES and national permit questions raised by clients, notification of reportable zoonoses, and welfare cases in which a husbandry failure amounts to neglect. You advise local authorities, pet shops and rescue organisations on husbandry standards and zoonosis control.
At research and specialist level the open questions are evidence questions. Much exotic pet therapeutics rests on single-species pharmacokinetic studies and allometric extrapolation; you design pharmacokinetic and efficacy studies, pain-assessment tools and anaesthetic monitoring validated for birds, reptiles and small mammals. You investigate the epidemiology of rabbit haemorrhagic disease variants, reptarenaviruses, bornaviruses and amphibian chytrids, including the role of the pet trade in moving pathogens between continents. You study the causes of ferret adrenal disease and the effects of different neutering methods, dietary causes of rabbit dental disease, reptile UVB requirements, and the welfare of species kept as pets, and you advise policy makers on trade controls and keeping restrictions using that evidence.
No therapeutic drug dose is given as a recommendation. Doses appear only inside worked arithmetic and must be confirmed against the product label and your national formulary; species differences in drug response are large and most uses are off-label. Normal physiological values, reference intervals, POTZ temperatures, UVB indices and humidity targets are given only in general terms because they differ by species and between texts. Vaccine availability for myxomatosis, RHD, canine distemper in ferrets and avian polyomavirus differs between countries and is not listed product by product. Surgical techniques (rabbit and rodent dentistry, ferret adrenalectomy, avian and reptile coeliotomy) are described only at the level of indication. Fish, invertebrates, hedgehogs, sugar gliders, skunks, primates kept as pets and venomous reptiles are not covered. The question of whether bird blood volume rules and reptile sample limits differ by species is left to formularies, and the clinical importance of the reptilian renal portal system and the use of oxygen during reptile recovery are presented as debated. National law is described in general terms only; check the current text of your country's welfare, trade and dangerous-animal legislation.
Original practice questions written to the syllabus and pattern of the exams named in each question's examTags. They are not past papers and do not reproduce any board's questions.
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