•   Obligate carnivores.

•   Caudal heart over the 6th to 8th rib.

•   Closed inguinal rings, one accessory sex gland the prostate.

•   Sebaceous glands, odour and browny-yellow secretion - discolours the fur.

•   Ferrets sleep for 18 hours a day with short energetic bouts of activity.

•   Seasonal weight loss is common during the summer months (up to 40%) and hair

  thinning. 

• Ferrets resent having their rectal temperature taken. An unbreakable digital plastic thermometer is best and the ferret may be distracted by a treat.

•   Dental disease is common ( tartar/gingivitis) especially on non-whole prey diets

•   Mucus membranes should be assessed for signs of anaemia in females.

•   Cataracts occur in both adult and juvenile animals.

•   Ear mites (Otodectes cynotis) are common with brown waxy discharge.

•   Peripheral lymph nodes should be palpated (enlarge with lymphoma).

•   The heart may be auscultated over the 6-8th ribs (more caudal than other species).

•   Abdominal palpation aided by holding the ferret in a semi-vertical position.

•   Splenic enlargement is commonly found in all animals and may be insignificant,

  although further diagnostic tests are indicated if this is found.

•   Females should be examined for vulval swelling which may be associated in the intact

  animal with oestrus and in the neutered animal with adrenal gland disease or rarely an ovarian remnant. 

0. Annual health checks are recommended. Ferrets should be vaccinated yearly against Distemper. A modified live vaccine offers the best protection, and it must not have been derived in ferret cell lines. A univalent vaccine licensed for ferrets is available in the USA, but not in the UK. Where no univalent vaccine is available, multivalent canine vaccines can be used at half the canine dose, but occasional adverse effects are reported. The first dose is given at 6-8 weeks of age, and then repeat doses are given every 3-4 weeks until 14 weeks of age. Annual boosters must be given to maintain protection. Adverse reactions can occur, with symptoms such as vomiting, diarrhoea, erythema, fever, and occasionally severe anaphylactic shock. Ferrets should be retained for 30 minutes after vaccination, and reactions treated with antihistamines, or adrenaline if severe. Owners should be advised if a product unlicensed for ferrets is used.

   Rabies vaccination should also be performed in the USA. This should be given annually. In some American states ferrets are illegal due to the threat of escape into the wild. American ferrets are also neutered prior to selling and genetically speaking are more inbred. Safe flea treatments in ferrets include fipronil, imidacloprid, selemectin, ivermectin and lufenuron. Imidcloprid is licensed for use in the UK. 

Pet passports  

can be issued for ferrets. Up to date information can be found on the DEFRA website. To enter or re-enter the UK from a listed country without quarantine a ferret must, in this order, be microchipped, vaccinated against rabies (Nobivac Rabies – Intervet) and issued with an EU pet passport or a third country official veterinary certificate and treated against ticks (any licensed product with marketing authorisation) and tapeworms (praziquantel). Tick collars are not acceptable. The following information should be recorded: Ferret’s date of birth/age; microchip number, date of insertion and its location in the animal; date of vaccination; vaccine manufacturer, product name and batch number; date by which the booster vaccination must be given, calculated by reference to the validity period of the vaccine according to the data sheet. There are no requirements for ferrets travelling directly between the UK and the Republic of Ireland. 

Routes for Parenteral Administration of Drugs in Ferrets 

As for other mammals a maximum of 1% of the ferret’s body weight may be safely collected. Sampling sites are listed below. Anaesthesia is required for safe sampling in most cases. The anterior vena cava/proximal jugular vein is the easiest site to consider. Given the heart location this is safer than in other small mammals. 

Urine may be collected by free catch using a litter tray. On average a ferret produces 24 – 30 ml of urine in 24 hours. Urine pH is acidic (6-7.5) and varies according to diet. Other collection techniques (cystocentesis, catheterisation) are performed as for cats and dogs. 

Splenic Aspiration and Bone Marrow Aspiration  

- Drugs may be given orally and should be directly administered rather than mixed in food. Medication may be mixed with food items such as peanut butter to encourage the ferret to take them. Intramuscular injections, if deemed necessary, should be given into the quadriceps or hamstrings. Ferrets can be easily distracted with food when performing procedures and Ferretone® is a very useful liquid vitamin supplement to use for these purposes. 

Fluid therapy requirements are calculated as in dogs and cats with maintenance of 75-100 ml/kg per day. Subcutaneous fluids are resented by ferrets and the animal should be scruffed prior to injection by this route or fluids given whilst under anaesthesia. The skin over the neck is extremely tough and a 23 or 21g needle should be used. In debilitated animals intravenous (cephalic vein) or intraosseous (prov=ximal femur/tibia) should be used. 

 may be provided in anorexic animals by syringe feeding liquid diets produced for supportive care of dogs and cats or those marketed for exotic carnivores. 2- 5ml should be fed 3-4 times daily. 

Radiography  

Sedation is essential in ferrets. The thorax is long and thin and the heart is positioned between the 6th and 8th rib with the apex to the left of midline. The cardiac shadow does not contact the diaphragm or the sternum normally. The ligament between the diaphragm and the heart contains fat and may be misinterpreted as cardiac enlargement. The mediastinum may contain large amounts of fat and this may make interpretation of thoracic radiographs difficult. Abdominal radiographs may be interpreted as in dogs and cats. Male ferrets have a J-shaped os penis. 

Ectoparasites  

Otodectes cyanotis is very common. Diagnosis and treatment are as for dogs and cats. Ivermectin is very effective. Note that many normal ferrets can have a profuse brown waxy aural discharge. Cat and dog fleas can also infest ferrets, and treatment is with products approved for these species. Spray or pump products should be measured carefully and applied to a cloth that is then applied to the ferret, to avoid overdose. Dichlorvos-impregnated flea collars are not recommended for ferrets because they can have toxic effects. Ticks can also affect ferrets, especially those used for outdoor hunting. Lyme disease has not been reported. 

Bacterial disease 

Bite wounds often become infected with Staphylococcus and Streptococcus spp., Corynebacterium, Pasteurella, Arcanobacterium and E.Coli resulting in abscesses, deep pyoderma or cellulitis. Treatment is by debridement and appropriate systemic antibiosis. Arcanobacterium pyogenes can also cause “lumpy jaw” type lesions in ferrets, and can respond to high dose penicillin or tetracycline. 

Viral disease  

A chin rash is an early presenting sign of distemper virus infection and mortality reaches 100%. 

Fungal disease 

Microsporum canis is the more common cause of ringworm in ferrets, although Trichophyton mentagrophytes is also seen. Transmission is often from co-housed domestic cats. Diagnosis and treatment are as for other species 

•   Mast cell tumours common and are usually benign. Single or multiple well- circumscribed raised hairless nodules that can become ulcerated.

•   Sebaceous epitheliomas and adenomas are common. Present as a pedunculated or plaque-like mass that can become ulcerated. 

0. Miscellaneous skin conditions  

0. Ferrets skin naturally contains numerous sebaceous glands, which cause the natural musky odour and sometimes greasy feel of the coat. Normal thinning of the coat occurs in warm weather, and a bilaterally symmetric alopecia of the tail, perineum and inguinal area can often occur during the breeding season. 

0. Adrenal Gland Disease 

0. is common in the USA and now in the UK. It occurs in middle- aged ferrets, associated with adrenocortical hyperplasia, adenoma or adenocarcinoma. There is a strong correlation between neutering and age at time of diagnosis (typically 3.5 years later). This has lead to concerns regarding routine neutering of ferrets. Alternatives include the use of desorelin implants every 18-24 months to suppress breeding activity. Clinical signs include bilateral symmetrical alopecia, pruritus (30% of cases) and vulval swelling in females (differentiate from hyperoestrogenism). Castrated males may show.

signs of male sexual behaviour. Partial or complete urethral obstruction secondary to prostatic hyperplasia may also occur and large prostatic cysts can be seen. Diagnosis - abdominal ultrasonography is most useful with visualisation of the enlarged adrenal glands. Plasma androgens, oestradiol or hydroxyprogesterone levels may be raised and all these steroid hormones should be assayed. These only confirm there is hormone producing tissue present and do not differentiate between an entire ferrets, ovarian remnants or adrenal gland disease. Treatment options are surgical removal and/or long term medical (hormonal) therapy. If both adrenal glands are grossly affected then removal of one and partial removal of the other is advocated. In unilateral cases improvement is seen in 2-8 weeks, with complete recovery in 5 months. Medical therapy alone should be used only in cases that are poor surgical candidates. Desorelin implants (GnRH agonist) are the treatment of choice for this condition. This eliminates clinical signs and decreases plasma steroid hormone concentrations. Studies indicate similar prognosis/longevity with surgical vs medical treatment. 

Hyperoestrogenism  

This is not commonly seen in the USA as the ferrets are neutered prior to sale. However in the UK it is common in entire females during the breeding season (Mar – Sept). If unmated, 50% may develop aplastic anaemia after prolonged oestrus (up to six months). Oestrogen suppresses the bone marrow, with resulting anaemia and pancytopaenia. Other causes of hyperoestrogenism include, ovarian remnants following ovariohysterectomy, or adrenal neoplasia. Clinical signs include a swollen vulva, vulval discharge, weakness, anorexia, pallor of the mucus membranes, systolic murmurs, weak pulses, melaena, alopecia over the tail base, ecchymoses and petechiation of the mucus membranes and skin, posterior paresis (due to haemorrhagic myelomalacia) and systemic infections secondary to leukopaenia. Diagnosis is based on history, clinical signs and haematology. Treatment includes supportive care and treatment to bring the ferret out of season. Intravenous fluids, nutritional support, iron and vitamin B supplementation and prophylactic antibiotics should be commenced. Blood transfusion is indicated if the PCV <15% (Normal values 46-61%). Blood groups have not been demonstrated in ferrets and therefore multiple transfusions from the same donor or a variety of donors without cross matching may be carried out without reactions occurring. Usually a large hob can supply plenty of blood for a transfusion. If >25%, cessation of oestrus may be curative. HCG may be used to make the ferret ovulate at 100IU IM, repeated after 7 days if signs of oestrus are still apparent. Proligestone or desorelin implants can be used as an alternative. Prevention is simple by using appropriate control of reproduction, which may include ovariectomy (given the previous discussion), mating with a vasectomised male, or proligestone injecition known as the jill jab, prior to the onset of the breeding season (side effects include pyometra and liver disease) or deslorelin implants. Altering of light cycles may prevent onset of oestrus in jills (14 hours light: 10 hours dark). 

Common in middle-aged ferrets in the USA and UK. The beta islet cells of the pancreas are affected, with increased insulin production and resulting hypoglycaemia. Clinical signs may be acute or chronic. In acute cases clinical signs include collapse, recumbency, depression, hypersalivation and a 'glassy-eyed' appearance. More chronic cases manifest as gradual weakness, particularly of the hind limbs, lethargy, ataxia, with or without weight loss and reduced appetite. Diagnosis is based on history, clinical signs, low blood glucose levels (care should be taken when recording a fasting level less than 3.33mmol/L) and a high or normal blood insulin level. Surgical or medical treatment is indicated, although neither is curative. Lifespan post-diagnosis and treatment averages between 6 - 24 months. Surgery is aimed at prolonging life span post-diagnosis with a nodulectomy or partial pancreatectomy being performed. Metastases are common. Medical therapy consists of oral prednisolone or diazoxide together or singly given orally twice a day. Ideally regular monitoring of blood glucose levels with gradual increases in dose when required should be performed. Ferrets should be fed regularly with high- protein, high-fat diets (dried ferret food, cooked meat). Foods with high sugar or carbohydrate levels should be avoided. Snacks should be fed after periods of sleep, when the ferret becomes more active, to coincide with when blood glucose levels are low and hypoglycaemia is more likely to occur. 

Foreign body ingestion is common in young animals that are allowed out unsupervised. In older animals trichobezoars are common. Presentation can be acute or chronic, but vomiting and regurgitation are rarely seen in the ferret, wherever the obstruction occurs. Anorexia, lethargy, weight loss, diarrhoea, ptyalism and pawing at the mouth may be seen. Objects in the stomach can be difficult to palpate as the stomach lies largely within the ribcage. Diagnosis is by radiography and contrast studies are not usually required. Surgical removal is indicated, although some trichobezoars may respond to laxative therapy. 

occur in animals of all ages, usually secondary to another disease. Helicobacter mustelae is the causal agent. Clinical signs include anorexia, lethargy, teeth grinding, ptyalism, diarrhoea and melaena. Ulcerations on the hard palate may be seen and abdominal pain is often evident. Positive diagnosis of Helicobacter infection is difficult as many labs are not equipped to culture it. Faecal tests may be useful but as most ferrets are assumed to be positive they can be difficult to interpret. Clinical signs, tissue biopsies, culture and response to treatment can all help to confirm diagnosis. Treatment of suspected disease is with metronidazole and amoxycillin given orally. Ranitidine, cimetidine or sucralfate can also be given. Supportive care such as fluids, iron supplementation and nutritional support may also be necessary. There is some logic in providing ranitidine as a preventative measure in ferrets receiving protracted therapy. 

Toxascaris leonina, Toxocara cati, Ancylostoma, Dipylidium caninum and Giardia spp can all affect ferrets. Coccidiosis is probably the most commonly seen parasite and can cause severe diarrhoea and rectal prolapse in young animals. Treatment is with sulfa drugs or toltrazuril. 

Similar to wet tail in hamsters and thought to be caused by Lawsonia intracellularis. It occurs in young ferrets, precipitated by stress. Acute colitis with tenesmus and green blood-flecked diarrhoea is seen in acute presentations. Diarrhea, haematochezia, anorexia, weight loss and rectal prolapse can be seen in chronic cases. Colonic biopsies reveal mucosal thickening and glandular epithelial hyperplasia. Treatment is with antibiotics such as tetracyclines and supportive care. Affected animals can die despite treatment. 

Epizootic catarrhal enteritis (ECE)  

a relatively new disease, first reported in the UK in 2010. Possibly caused by a coronavirus, the disease is highly infective, with people acting as fomites. Affected animals apparently recover only for the disease to recur, and older ferrets develop a more severe form of the disease. Clinical signs are anorexia, lethargy, green diarrhoea and melaena. Treatment is with supportive care including antibiotic cover, and affected animals should be isolated. 

Congestive (dilated) cardiomyopathy 

 common in ferrets. Clinical signs are generally nonspecific and include lethargy and dyspnoea. Auscultation reveals tachycardia and often muffled heart sounds. Pleural effusion and ascites may be seen. Diagnosis is by radiography and ultrasonography (increased ventricular dimensions, reduced fractional shortening and an enlarged left atrium). Treatment is similar to other species. 

Canine Distemper Virus 

Ferrets are highly susceptible. Clinical signs consist of a rash on the chin, dermatitis of the perineum, anorexia, pyrexia, depression, photophobia and blepharospasm. A mucopurulent oculonasal discharge is often present, and followed by coughing and sneezing. Secondary bacterial respiratory infection is common. Hyperkeratosis of the footpads is also seen. CNS signs such as incoordination, torticollis, and nystagmus are seen in ferrets with advanced infection. Infection is fatal. Transmission is mainly by aerosols. The incubation period is 7 –10 days. Control is by vaccination. 

Aleutian Disease of Ferrets 

 caused by a parvovirus. Vertical and horizontal transmission occurs. Clinical signs include posterior ataxia, paresis or paralysis with a generalised malaise, tarry faeces and weight loss. Disease is immune-mediated and hypergammaglobulinaemia (>20% TSP) is highly suggestive. Liver enzymes are NOT raised. Serology (Harlan Olac Ltd) and virus isolation confirm diagnosis. Histopathology of liver, kidney, spleen, meninges shows lymphocytic infiltration. No treatment or vaccine is available. Euthanasia should be carried out in severely affected animals, but supportive treatment can be attempted in mild cases. 

Influenza - 

very susceptible to many strains of human influenza virus, and transmission can occur from man to ferret and vice versa. The symptoms are similar to those of distemper but less severe, with a serous nasal discharge rather than mucopurulent. Coughing and sneezing are prominent features of infection. It is usually self-limiting and rarely fatal, although supportive care may need to be given. This includes swine flu variants. 

Lymphoma 

the third most common neoplasia (after insulinoma and adrenal gland disease). There are two distinct forms - juvenile (lymphoblastic), which is the more aggressive form, and adult (lymphocytic). Clinical signs in adults are usually non specific (loss of appetite and weight loss), and enlarged peripheral and/or internal lymph nodes are frequently palpable on physical examination. In juveniles, typical signs are pleural effusion leading to dyspnoea and coughing and organ enlargement.
Diagnosis is based on radiography, ultrasonograhy, including ultrasound-guided FNA, FNA of enlarged lymph nodes, or surgical removal/excisional biopsy (popliteal), bone marrow biopsy, thoracocentesis, cytology and haematology. Symptomatic treatment includes thoracocentesis in cases with pleural effusion, general supportive care including nutritional support. Numerous chemotherapeutic protocols are reported including glucocorticoids alone, COP protocols, single agent doxorubicin, combination doxorubicin and radiation, and high dose vincristine. The lack of a single protocol signifies that there is no universally ideal protocol. In general, response in ferrets is poor and survival times may be brief. Mean survival times of 6 months for high grade lymphoma and 10.6 months for other types are reported. Radiation therapy is increasingly used in the USA as both primary and ancillary treatment. 

Splenomegaly  

 common in ferrets, and can be due to extramedullary haematopoiesis, neoplasia or chronic inflammatory disease. The spleen can undergo a 15-35% increase in size with any anaesthetic. If the spleen is persistently enlarged in a ferret <3yrs it is likely to be neoplastic. Surgical removal is indicated if neoplasia is suspected or confirmed, or if the organ is causing obvious discomfort. Bone marrow function should always be assessed before removal, as the spleen may be the only site of erythropoiesis. 

Pre-anaesthetic Considerations  

 Prior to anaesthesia always carry out a thorough clinical examination to assess whether there is any underlying disease. Correct any fluid deficits. Weigh the animal, so accurate drug dosages can be calculated and fluid losses can be assessed. Ferrets should be fasted prior to induction for 4 – 6 hours, with water being removed 2 hours prior to induction. 

Sedation and Premedication  

 Ferrets readily salivate, particularly when induced with a ketamine combination. Ferrets are very easily stressed by restraint, so sedation is vital, especially prior to induction by inhalation. ACP, midazolam, medetomidine, alfaxalone or ‘Hypnorm’ may used. 

Injectable Anaesthesia – medetomidine/ketamine is the author’s preferred induction regime, although combinations are possible, such as fenyanyl/fluanisone or diazepam/alfaxalone. 

Inhalation Anaesthesia – Isoflurane or Sevoflurane can be used in fractious animals for induction in a chamber or with physical restraint. Prior sedation should be used in most cases. Maintenance with inhalation agents is as for cats. Ferrets can be easily intubated. 

Intra-operative Care and Monitoring  

is as for cats or dogs, with hypothermia a concern can this should be both measured with a rectal digital thermometer and remedial action taken. 

Post-anaesthetic Considerations 

Analgesia  

 Buprenorphine is the drug of choice, as it is the longest lasting (8 - 12 hours). Buprenorphine and butorphanol will reverse the respiratory depressant effect of fentanyl while still providing analgesia. Atipamezole will reverse the sedative effects of alpha-2 agonists, but will NOT provide analgesia. NSAID's can also be used for post-operative analgesia, e.g. carprofen, meloxicam. Local anaesthesia should also be employed where possible. 

Ovariohysterectomy – ot routinely recommended but still appropriate in some cases ( eg rescue/rehomed animals). A discussion of the pros and cons of neutering should be had with any owner prior to a decision being made as the ferret may be predisposed to adrenal gland disease. If a female is going to be spayed this should be performed from months onwards preferably before their first oestrus. The ferret uterus is bicornuate and similar to dogs and cats. Ovariohysterectomy is carried out using a midline ventral abdominal incision, the technique being similar to that used in bitches. The suspensory ligaments are slack and do not need to be broken down. Deslorelin implants nay be placed in neutered animals to prevent the development of AGD. 

Castration  

Not routinely recommended but may be appropriate in some cases ( eg rescue/rehomed animals). A discussion of the pros and cons of neutering should be had with any owner prior to a decision being made as the ferret may be predisposed to adrenal gland disease. Males may be castrated from 6-8 months old. It may be of benefit in aggressive pets and also to reduce the sebaceous gland secretions, which produce the ferrets musky odour. Rarely testicular neoplasia is encountered (interstitial cell and sertoli cell tumours). The testes are situated caudoventrally in the scrotal sac, in a similar anatomical position to cats. Castration is carried out as for cats using either a closed or open castration technique. The scrotal incisions are left open. Recently castrated and vasectomised male ferrets should be kept apart from the female for up to 6 weeks post-operatively to allow healing and prevent possible sterile matings. However desorelin implants have been reported to reduce odour, shrink testicular size and alleviate any behavioural signs. Deslorelin implants may also be placed in neutered animals to prevent the development of AGD. 

Retains the ferret's urge to mate, however the mating is infertile and brings the female out of oestrus. Place in dorsal recumbency and surgically prepare the prescrotal area. The vasectomy is performed through two prescrotal incisions. The cord is palpated prior to making the incision. There is a deep layer of subcutaneous fat in this area which needs to be dissected. The cord may then be visualised. Gentle traction on the testes helps to locate the cord through the fat. Extreme care should be taken to avoid the urethra. Once the cord is located it is exteriorised using a pair of artery forceps, which are looped under it. A careful incision is made in the tunica to expose the vas deferens medially. This may have a small vessel associated with it, but is distinct from the vascular plexus and cremaster muscle, which are placed laterally. The vas is palpable as a firm thickened band, which may be rolled across your finger. Ligatures are placed 1-1.5cm apart and the cord between them is excised. One end of the ligated cord is sutured into the tunica on closure to further prevent reanastomosis. The tunica is closed using a continuous absorbable suture pattern. Closure may be difficult if the vascular plexus has become engorged. Single continuous absorbable sutures are placed in the subcutaneous fat and subcutis. The procedure is repeated for the other side. Scrotal swelling is common post-operatively and may require anti-inflammatory treatment and analgesia for 2-3 days. 

'Descenting' or Anal Sacculectomy  

this is not performed in the UK, since is does not remove a ferret's odor and is a 'cosmetic' operation. The RCVS has this procedure on the list of mutilations. Owners will often enquire about this procedure and so it is important to be aware of the technique.