Ferrets are carnivorous, with a short gastrointestinal (GI) tract and a rapid transit time. Therefore, any disturbances in the GI are quickly obvious, including diarrhea and anorexia. Many non-GI conditions in ferrets will present with concurrent diarrhea or lack of appetite. We will discuss the primary GI conditions below grouped by age.
Gastrointestinal foreign bodies: Young, inquisitive ferrets most often consume inappropriate objects. Foam rubber, sponge, and rubber are commonly ingested. Ferrets usually stop this behavior by 12 months of age, although occasionally an 18 month old will consume foreign material. Even when not observed, ferrets who have free roam of a room or a household, or are minimally supervised, are the most likely to encounter and ingest foreign material.
Unlike dogs, ferrets with foreign body ingestion do not often vomit. Anorexia, scant diarrhea, and lethargy are common presentations. Due to the compliant and extensively exposed abdomen, the GI tract of ferrets is easily palpated. Radiographs will usually demonstrate abnormal gas patterns in the GI as well as gaseous distention of the stomach. Ultrasound can also help confirm the diagnosis of obstruction.
Coccidia and Giardia are occasionally seen in young ferrets as causes of diarrhea. The coccidian species are specific to ferrets. Treatment with oral medications are usually curative.
Proliferative bowel disease is now uncommon in ferrets in the U.S. It was seen in previous decades, usually in very young ferrets. The first signs include acute colitis, tenesmus, frequent defecation and rectal irritation. Definitive diagnosis requires colonic biopsies and histopathology although response to medication is used for a tentative diagnosis if the ferret’s health preclude obtaining biopsy samples.
Any ferret with severe or chronic diarrhea that has had the anal sacs removed will be prone to rectal prolapse. Treatment of the underlying condition is usually sufficient, but many ferrets in the US, where anal sacs are removed at a very young age, may have a residual prolapse that occurs transiently during defecation.
Inflammatory Bowel disease: Eosinophilic Enteritis and Lymphocytic-Plasmacytic Enteritis
These diseases are often grouped together due to the similar clinical signs and the non-specific nature of the GI inflammation that they represent. Clinical signs include mild to moderate weight loss, decreased appetite, diarrhea and decreased activity.
This disease syndrome appears to be a reaction to some agent to which the GI is sensitive. This may be a food allergy, bacterial sensitivity, parasitic reaction or even a reaction to agents that are normal within the ferret’s body. Multi-systemic eosinophilic disease also occurs, which may involve the liver, respiratory tract, lymphatic system, and isolated eosinophilic infiltrates. The specific cause of this syndrome is often not identified, but most cases are responsive to medication. Some ferrets will recur with inflammatory bowel disease when the therapy is discontinued, while others may be successfully tapered off of therapy.
Lymphocytic Plasmacytic Enteritis
This syndrome has been identified more recently than has eosinophilic enteritis. Clinical signs are similar to those of eosinophilic enteritis but are minimally responsive to treatment with only glucocorticoids. Etiology may vary and be multifactorial. In a significant number of cases corona virus of ECE, and/or Helicobacter m. is identified on immunohistochemical stains of intestinal biopsy sections. The general theory of IBD is that it is caused by the intestinal loss of tolerance to antigens to which it is exposed. These antigens may be food, bacteria, auto antigens or other substances. Treatment is aimed at modulating GI immune response, preventing or treating intestinal bacterial overgrowth and preventing gastric Helicobacter ulceration.
A high percentage of ferrets are likely colonized with Helicobacter m. With Helicobacter gastritis, gastric ulceration and hemorrhage may cause either the vomitus or the stool to contain denatured blood. These ferrets are generally very painful upon gastric palpation. Bruxism, ptyalism, and aversion to food are common. The prevalence of Helicobacter m. enteritis seems to be rising, though that impression may be skewed by an increased awareness of its existence, (partially due to research on the pathophysiology of the same bacterial genus in gastric ulcers of people) and an increase in histopathology submissions. Affected ferrets are often adults, although the syndrome is also reported in juveniles. Often the stress of a concurrent syndrome, such as an insulinoma or adrenal disease, may precipitate the clinical manifestation of an infection. These ferrets seem to be in considerable distress, and may exhibit facial and ear “twitching” and pawing at the mouth. Antibiotic combinations may be prescribed.
E.C.E. (Epizootic catarrhal enteritis, Corona viral enteritis, or Green Slime Disease)
This diarrheal disease is likely that the cause is a corona virus but no vaccination is currently available for this disease. An apparent latent carrier state is established in many recovered ferrets that persists for an indefinite period of time. Recurrences of the disease in the same ferret have been documented. Clinical signs generally include severe, fluorescent, watery, light green diarrhea, generally after recent exposure to a newly introduced but asymptomatic ferret. In young, healthy ferrets, very little treatment other than supportive care is required. Older ferrets with concurrent problems are the ones at risk for complications, including severe dehydration, emaciation, and death. The incubation period is extremely short, and the disease is highly contagious.
Note: Realize that ferrets often have a green, (especially dark green) stool or diarrhea from a variety of other illnesses.
Overgrowth of Clostridial bacteria is fairly common in ferrets. The diarrhea usually has a very foul odor. Most ferrets are not clinically ill with Clostridial overgrowth, but it does tend to occur in older ferrets that may have other metabolic or gastrointestinal issues (i.e. previous ECE, Helicobacter, IBD, adrenal disease or insulinoma episodes). Clostridium are recognized on a Gram’s stain as either bipolar or “safety pin” appearing gram-positive staining rods. Medications control the overgrowth and clinical diarrhea in most ferrets, but recurrence is common.
Various non-gastrointestinal syndromes may cause clinical signs of diarrhea, anorexia, nausea, and occasionally vomiting. These include renal failure, liver disease (including hepatic lipidosis and lymphoma) insulinoma, systemic viruses, autoimmune diseases, and various neoplastic conditions.