When Your Ferret Is Sick

Ferrets have become quite popular as pets, and for good reason. These winsome mammals are intelligent, inquisitive and good-natured. Ferrets sold in the pet trade have already been neutered (spayed or castrated) and descented or demusked. A ferret that is fed a good-quality diet and is cared for properly should remain healthy through middle age and live between 5 and 8 years. Most ferret diseases occur as they get older, with a few notable exceptions.

Green Slime Disease

Epizootic catarrhal enteritis is also called "green slime disease" because within a week or two of exposure, adults become listless and develop green, slimy feces. Young ferrets are rarely infected but adult ferrets are susceptible and usually become exposed by having an owner play with baby ferrets in a pet store, then return home to handle their own adult ferrets. The disease may also be introduced into the household when ferret owners bring home a new baby ferret. A ferret with ECE may have a decreased appetite and may develop a fever.

Any ferret suspected of having ECE should be evaluated by a veterinarian familiar with ferrets. ECE is suspected of being viral, but there is no specific antiviral therapy available at this time. Most ferrets with ECE are dehydrated and require fluid therapy. Often antibiotics are administered to prevent secondary infections, and antidiarrheals are usually given. It is very important for a sick ferret to continue eating, since a ferret that is not eating will quickly develop liver damage (called hepatic lipidosis). If the animal will not eat, he may need to be gently force-fed, using a syringe or spoon.

Most ferrets will recover from ECE within a few weeks. Some may require hospitalization and intensive care. Rarely, a ferret will have diarrhea for months after infection, due to inflammation in the bowel, which may require treatment with anti-inflammatory drugs.

At this time, no vaccination can prevent ECE. If you have adult ferrets, it is best if you don't handle other ferrets, especially youngsters, and if you have an established family of ferrets, it is best not to introduce a new young ferret.

Digestive Problems

Ferrets are true carnivores and should only be fed a good quality ferret diet or, if that is unavailable, good quality kitten or cat food. They cannot tolerate more than 4 percent fiber in their diet. An inappropriate diet may cause gastrointestinal problems.

Young ferrets are very curious and may accidentally eat portions of a toy or non-digestible items found around the house. This may result in a blockage that requires surgery.

Ferrets may harbor one of several types of bacteria that can cause gastritis (inflammation of the stomach) and, on occasion, ulcers. The most common bacteria is called Helicobacter. Ferrets with gastritis may vomit or have diarrhea. The stool may be black and tar-like if the ulcer is bleeding. If untreated, ferrets with gastritis may lose weight and become dehydrated. Antibiotics are prescribed to treat gastritis, and other medications may be necessary, as well.


Ferrets may suffer from flea infestations that can be controlled with prescription medication from your veterinarian. They may occasionally have ear mites, which cause a brown, odiferous secretion in the ear canals. Ferrets with ear mites often scratch at their ears excessively. Ferrets may also acquire heartworms from the bite of an infected mosquito. For ferrets at risk, preventative heartworm medication can be prescribed by a veterinarian and administered daily or monthly.

Endocrine Troubles

Insulinoma is a common disease of middle age. A tumor in the pancreas causes problems with the cells that produce insulin, the hormone that controls blood sugar levels. A ferret will develop symptoms associated with low blood sugar. Early signs may include a glassy-eyed appearance and increased salivation. Often, the ferret is depressed and may not respond to being held, petted, picked up, or having his name called. The ferret may collapse and then, after a short period, recover. A gradual onset of weakness may occur over a period of weeks or months. Periods of weakness and wobbly gait, with the hind legs being obviously affected, may be separated by periods in which the ferret may appear perfectly fine. Diagnosis is made through blood testing, ultrasound or surgery. Treatment is by medication or surgery.

Tumors of the adrenal glands often cause a bizarre group of symptoms. These glands, one near the top of each kidney, produce hormones, predominantly corticosteroids. Glands with tumors produce excessive amounts of sex hormones. Affected ferrets suffer symmetrical hair loss or thinning, especially over the back, hips, rump, tail and thighs. The ferret may appear very itchy where the hair is missing. The hair loss is often progressive and typically begins in the late winter or early spring and it may continue until the ferret is bald, or the hair may regrow in the fall, only to begin another hair loss cycle the following winter or spring. Over 90 percent of the ferrets with adrenal disease show some hair loss. Many spayed females with adrenal disease have enlarged external genitalia. Males often suffer partial or complete blockage of the urinary tract.

A veterinarian may be able to feel an enlarged gland. X-rays and ultrasound may be necessary. A blood test is the best way to diagnose adrenal disease in ferrets. While adrenal disease can be managed medically, surgical removal of the diseased gland is the preferred method of treatment.


Lymphoma may occur in young ferrets (as young as 4 months of age) or in adults. The disease is highly variable and may be acute or chronic. The ferret may act lethargic and may lose weight. The lymph nodes may be enlarged. The disease may affect almost any organ system, so signs will vary depending on which organs are being damaged. This disease may be diagnosed through blood tests, radiographs, biopsy of a lymph node, spleen, liver or bone marrow. Chemotherapy may bring on remission of the disease for varying periods of time. Surgical removal of any large, solitary masses may be helpful.