Gastrointestinal Diseases in Ferrets

Gastrointestinal (GI) conditions are fairly common in ferrets. From dental disease to inflammatory bowel disease, coronavirus enteritis to gastrointestinal foreign bodies, ferrets may develop a wide variety of conditions that affect their digestion and defecation.

Some conditions, such as intestinal foreign bodies, are readily prevented and easily resolved with medication or surgery, while others require considerable diagnostic investigation and may need long-term treatment.

Dental Disease

Ferrets two years of age and older may be affected by dental tartar, gingivitis (gum inflammation), periodontal disease, or frank dental decay. These problems are more common in animals fed moist (canned) diets, although even on a dry diet, tartar may accumulate as the animal ages.

Regular (weekly) brushing with dog or cat toothpaste can help control tartar. If you start brushing your ferret’s teeth at a young age, you can avoid most dental issues. In some cases, an annual dental cleaning done under anesthesia may be necessary to remove the tartar build-up and control any inflammation or infection of the gum tissue.

Chewing and gnawing on objects may help prevent the build-up of tartar, but these habits can lead to tooth damage, such as fractures (breaking) of the long canine teeth or molar teeth. Fractured tooth tips are not necessarily a problem, unless there is exposure of the dental pulp. Tooth root abscesses can occur but are not common in pet ferrets.

Gastrointestinal Foreign Bodies

Ferrets are inquisitive and love to chew just about anything. They often swallow rubber, foam, or plastic objects. This chewing is especially a problem in young, inquisitive ferrets, but can happen in older ferrets too. Swallowing an object (foreign body ingestion) may lead to an obstruction in the intestinal tract. Gastric (stomach) or intestinal obstructions may also be caused by hairballs or by tumors in older ferrets.

The key signs that a ferret has a gastrointestinal foreign body are severe lethargy (lack of energy), anorexia (reduced appetite) with or without vomiting, and a reduced volume of feces. Although one would expect vomiting to be the main sign, that is not always the case. Foreign objects in the small intestines often cause severe pain. 

Your veterinarian may be able to palpate (feel) the intestinal foreign body if your ferret is relaxed. Objects in the stomach cause less pain and are more challenging to feel by means of abdominal palpation. Foreign bodies in the small intestines are more likely to cause a blockage due to the small diameter of the intestinal tract.

Gastrointestinal foreign bodies may be difficult to diagnose without further testing. Radiographs (X-rays) can help identify most types of gastric or intestinal foreign bodies. In some cases, a barium contrast series will be recommended, in which your veterinarian will administer oral barium to your ferret and then take X-rays at timed intervals. Barium often shows the site and size of the obstruction, even if the object is not visible on the survey X-ray.

Exploratory surgery of the abdomen is often necessary to remove and resolve the obstruction caused by a foreign body, hairball, or a tumor. If a gastric or intestinal foreign body obstruction is diagnosed and treated early, most ferrets recover well from surgery to remove it. Prevention is obviously preferred and ferrets should not have access to objects that can be chewed and swallowed. Ferret-proof your house!

Parasites

Gastrointestinal parasites are rarely seen in ferrets, but any ferret with diarrhea should have a microscopic fecal examination. While gastrointestinal worms or eggs are rarely seen, protozoa such as Giardia or Coccidia may be noted. Intestinal protozoa can cause persistent diarrhea and/or a rectal prolapse (protrusion of anal or rectal tissue). Treatment with anti-protozoal medications should resolve the infection and subsequent intestinal upset caused by the protozoa.

Diarrhea

Diarrhea is not a disease, but rather a sign of a gastrointestinal problem. Diarrhea can range from liquid to semi-solid feces. Depending on the cause, feces may be dark-colored, green, mucoid with a slimy appearance, or granular and “seedy” with a semi-liquid consistency. Ferrets with diarrhea may not be visibly sick, or they may show anorexia, vomiting, weight loss, depression, lethargy, or dehydration.

In ferrets, a variety of conditions may cause diarrhea, including intestinal parasites such as Coccidia and Giardia, and several viral diseases that may involve disease of the intestinal tract. The more commonly noted viruses are:

• Rotavirus (seen in young ferrets in North America)
• Epizootic catarrhal enteritis (ECE), a form of coronavirus that affects the intestinal tract and typically involves very young ferrets
• Human influenza or canine distemper (a fatal disease in most ferrets)

Some bacteria can be involved in diarrhea in ferrets, such as Helicobacter mustelae (a spirochete-type of bacteria), Salmonella, Campylobacter (proliferative colitis), and Clostridia. Salmonella and Campylobacter are important zoonotic diseases, meaning they can spread to humans. Supportive veterinary care is essential in any case of diarrhea in these small mammals, since fluid loss can be fatal. It is also critical to have a specific diagnosis since some conditions are transmissible to other ferrets or humans.

Gastritis

Gastritis means inflammation of the stomach. In humans, Helicobacter pylori has been identified as a significant factor in stomach ulceration. In ferrets, Helicobacter mustelae has been similarly found to be associated with stomach ulceration and inflammation. This organism can cause stomach ulcers with gastrointestinal bleeding. It is reported that almost 100% of ferrets have Helicobacter in their stomach by the time they are weaned, but not all ferrets develop symptoms of illness.

Stress is an important factor in the development of gastritis due to Helicobacter mustelae. Stressors can include changes in environment or diet, such as that which occurs when young animals are moved from their mother to a pet store, and then from the pet store to their new home. Other stressors may contribute to an overgrowth of Helicobacter bacteria and subsequent diarrhea, such as an overbearing older ferret, a playful cat or dog, or an uncleaned cage. 

If these young, infected, and stressed animals meet an older family pet ferret, that animal may become sick as well. Treatment of this disease requires a combination of antibiotics, together with gastrointestinal protectants and supportive care such as fluid therapy.

Proliferative Bowel Disease (PBD)

Proliferative bowel disease (PBD) in ferrets is like PBD in pigs and hamsters. It is caused by an organism called Lawsonia intracellularis. It is most common in young, fast-growing ferrets (10–16 weeks old) and can be linked to environmental and nutritional stresses. Infection causes a thickened lower bowel, which results in chronic mucoid, green diarrhea and/or a rectal prolapse. Affected animals make a rapid recovery when treated with the appropriate antibiotic therapy.

Eosinophilic Gastroenteritis

Eosinophilic gastroenteritis is relatively common in ferrets. It is an inflammatory disease of the stomach and/or intestinal tract, and the classic symptom is chronic diarrhea, with or without mucus or blood. While food allergies have been suggested as a cause of eosinophilic gastroenteritis in people and dogs, no such link is obvious in ferrets. An elimination diet may help in diagnosing this condition. Eosinophilic gastroenteritis can be a frustrating disease to treat.

Differentiation of the causes of diarrhea and wasting can be difficult. Supportive care is essential, since these small animals are very easily compromised by fluid and nutrient loss. All cases of diarrhea, vomiting, or gastrointestinal disorders must be brought to the attention of your veterinarian as soon as possible. Veterinarians who are members of the Association of Exotic Mammal Veterinarians (https://aemv.org) are usually more adept at treating ferrets with gastrointestinal disorders.