Working up gastrointestinal disease in the ferret (Proceedings)


Working up gastrointestinal disease in the ferret (Proceedings)

Apr 01, 2008

Gastrointestinal disease is common in pet ferrets and is frequently accompanied by weight loss and wasting. Unique anatomy and physiology, including rapid gastrointestinal transit time and short, simple gastrointestinal tract makes the ferret predisposed to gastrointestinal disease. Ferrets are used as laboratory model for a number of human disorders involving the gastrointestinal tract, including gastric and intestinal ulcers, gastric carcinoma and helicobacter gastritis.1 Etiologies are many, can be multi-factorial, and can include foreign body-related disease, bacteria, virus, neoplasia, inflammatory conditions, stress and dietary change. Gastrointestinal disease, in particular diarrhea, can be secondary to the stress of other primary non-GI related diseases. Some practitioners report improvement in some refractory cases with diet modification, which suggests dietary allergen or intolerance. A thorough work up is critical for distinction between etiologies typically producing similar clinical signs and symptoms.1,2

Specific Gastrointestinal Diseases in the Ferret

Table 1. Diseases producing intermittent or chronic diarrhea in ferrets.
It is beyond the scope of these proceedings to describe all causes of diarrhea in ferrets in detail. A list of both documented and anecdotally reported contributors are listed in Table 1. Keep in mind that many cases involve more than one disease process and can be complicated by psychologic stress. Therefore, ANY disease process could contribute to diarrhea in the ferret.

Working Up Gastrointestinal Disease in the Ferret

Working Up Gastrointestinal Disease: the History and Physical Examination

While working up gastrointestinal disease in ferrets is seldom straight forward, careful attention to history and signalment may reveal some important patterns. Ferrets under one year of age are more prone to foreign body ingestion, coccidia and proliferative colitis, while coronavirus and Helicobacter mustelae typically affect older ferrets.1,2 Diarrhea occurring soon after introduction of a new ferret into the household could suggest an infectious etiology, such as coronavirus, coccidia or possibly giardia. Infectious agents such as Lawsonia and Mycobacteria, however, tend to affect only a few members of a group.1,2 Diarrhea occurring soon after an unusual event such as travel, veterinary visit, change in social structure (addition or loss of a social companion) or normal routine may reflect stress and not underlying disease.

While some assumptions can be made based on clinical signs and history, it is impossible to diagnosis specific gastrointestinal disease based on observations such as the color and character of diarrhea. In other words, "green slime" does not always equal epizootic catarrhal enteritis (ECE), and making such an assumption can delay proper diagnosis and treatment.

Working Up Gastrointestinal Disease: Clinical Pathology

Considering the numerous etiologies of ferret gastrointestinal disease, workup must be thorough. Complete blood count (CBC) and chemistry panel are non-specific but can provide clues to diagnosis and help evaluate overall patient condition. In many cases, biochemical changes simply reflect patient dehydration, anorexia and wasting. Anemia can occur from chronic inflammation and/or blood loss.

Routine culture and sensitivity can help identify primary or secondary bacterial pathogens. Helicobacter mustelae is a common pathogen of ferrets, but cannot be identified on routine culture. Biopsy and histopathology of gastric samples, and/or PCR of gastric, colonic and/or mouth swabs provide a more specific diagnosis. As Helicobacter mustelae is thought to be present in nearly all ferrets, and apparently does not always produce disease, the most useful application of PCR may be to monitor response to therapy and detect reinfection. 4

Working Up Gastrointestinal Disease: Radiography and Ultrasound

Radiography can be useful in the diagnosis of gastrointestinal disease. Abnormal gas patterns can suggest foreign body obstruction or enteritis. Survey radiographs can often reveal evidence of GI masses or thickened bowel loops. Contrast media have been used to evaluate the gastrointestinal tract. A recent study on results of the use of barium sulfate, 8-13 ml/kg, indicated that small intestinal transit time was less than 2 hours. Visualization of the barium-filled small bowel was optimal at 20 and 40 minutes post barium administration. Small bowel loops in these normal ferrets did not exceed 5-7 mm in width. The use of ketamine and diazepam to facilitate radiography did not significantly slow GI transit time in these ferrets.24