Feline inflammatory bowel disease (IBD) is a chronic condition that affects a cat’s gastrointestinal tract, leading to persistent irritation and inflammation. This inflammation causes inflammatory cells to infiltrate the GI tract walls, resulting in thickening and impaired digestion and nutrient absorption. While cats of any age can develop IBD, it is most commonly observed in middle-aged to older felines.
The exact cause of IBD remains unknown. However, current research suggests a complex interplay between the immune system, diet, intestinal bacterial populations, and other environmental factors. Similar to IBD in humans and dogs, genetic predispositions in the immune system are also believed to contribute to the development of this condition in cats.
IBD can manifest in various forms depending on the affected area of the GI tract and the specific types of inflammatory cells involved. Inflammation of the stomach is termed gastritis, inflammation of the small intestine is enteritis, and inflammation of the large intestine is colitis. The most prevalent form is lymphocytic plasmacytic enteritis, characterized by the invasion of lymphocytes and plasma cells into the small intestine. Eosinophils, a type of inflammatory white blood cell, are also frequently implicated in feline IBD, occasionally being the predominant cell type (eosinophilic gastroenteritis) but more often appearing as part of a mixed inflammatory cell population. Less common forms include neutrophilic IBD and granulomatous IBD. In some instances, IBD may be associated with inflammation in other abdominal organs, such as the liver and pancreas.
Clinical Signs of Feline IBD
Common symptoms associated with feline IBD include vomiting, weight loss, diarrhea, the presence of blood in stools, lethargy, and a decreased appetite. The severity and frequency of these signs can vary significantly, and the predominant symptoms often depend on which sections of the GI tract are affected. For example, inflammation in the stomach or upper small intestine may lead to chronic vomiting, while inflammation in the colon is more likely to cause diarrhea, potentially with blood.
Diagnosis and Diagnostic Procedures
Diagnosing feline IBD can be challenging because many of its signs overlap with those of other diseases. Your veterinarian will likely recommend a comprehensive diagnostic workup. This typically includes baseline blood tests, fecal examinations, X-rays, and possibly an abdominal ultrasound to rule out metabolic diseases, feline leukemia, parasitic or bacterial infections, hyperthyroidism, and certain types of cancer. Intestinal lymphoma, a serious cancer, can be particularly difficult to differentiate from IBD in cats. Measuring blood levels of B vitamins like B12 and folate can also be helpful, as IBD can impair their absorption. A hypoallergenic food trial may also be conducted to determine if food allergies are contributing to the symptoms.
A definitive diagnosis of feline IBD ultimately requires obtaining a biopsy of the intestinal or gastric tissue and examining it under a microscope. Increased numbers of inflammatory cells within the intestinal wall are indicative of IBD. The specific types of inflammatory cells present help to classify the type of IBD and guide treatment strategies. Intestinal biopsies can be performed via endoscopy, where a flexible camera is passed through the mouth or rectum, or through abdominal surgery. While endoscopy is less invasive, surgery may be preferred if inflammation of the liver or pancreas is also suspected, allowing for biopsies of these organs as well. Both procedures require general anesthesia, and the associated risks must be carefully considered.
Treatment Approaches for Feline IBD
Veterinary treatment for feline IBD typically begins with addressing any intestinal parasites and implementing a combination of dietary modifications and medications. There isn’t a one-size-fits-all treatment, so your veterinarian may need to experiment with different dietary and medicinal combinations to find the most effective therapy for your cat.
Dietary Management Strategies
Given that dietary allergens can play a role in IBD, your veterinarian might suggest a food trial using hypoallergenic diets. These diets feature protein or carbohydrate sources that the cat has not been exposed to previously, such as rabbit, duck, or venison. If symptoms don’t improve with a hypoallergenic diet, options like high-fiber, low-fat, and easily digestible foods may be recommended. It is important to note that it can take several weeks, or even longer, for cats to show improvement after a dietary change. During any food trial, it is crucial to eliminate all other food sources, including table scraps, flavored medications, and treats.
Medical Interventions
Metronidazole is often the first medical therapy recommended alongside dietary changes. This medication possesses antibiotic, anti-inflammatory, and antiprotozoal properties and is generally well-tolerated, though some cats may experience a loss of appetite.
If dietary management or metronidazole proves ineffective, corticosteroids, which are powerful anti-inflammatory and immune-suppressing agents, may be prescribed, either alone or in conjunction with metronidazole. Cats on corticosteroids require close monitoring due to potential side effects such as diabetes and immune suppression. However, cats typically tolerate these drugs well when administered at appropriate doses. Corticosteroids are usually given orally, starting with a higher dose that is gradually reduced over several weeks. For cats that refuse oral medication or experience severe vomiting, your veterinarian may administer injections.
In cases where these medications do not sufficiently control IBD symptoms, more potent immunosuppressive drugs like chlorambucil or azathioprine might be necessary. These drugs can suppress the production of white blood cells, red blood cells, and, less commonly, platelets in the bone marrow. Cats receiving these medications require careful monitoring by a veterinarian. Newer therapeutic approaches also include prebiotics and probiotics, aimed at modulating the gut bacteria. Supplementing with soluble fiber, such as psyllium, can be beneficial for cats with inflammatory colitis, and folate or vitamin B12 supplementation should be provided if deficiencies are detected.
Prognosis for Cats with IBD
While feline IBD can often be managed effectively, allowing affected cats to live healthy and comfortable lives, symptoms may still fluctuate. Strict adherence to prescribed dietary and medical therapies is essential for disease control. Regular monitoring by both the veterinarian and the owner is critical for assessing relapses and adjusting long-term medication dosages as needed.
