DM3 Pt3-3 Inflammatory Bowel Disease (IBD) Flashcards
What is Inflammatory Bowel Disease (IBD) in cats?
IBD is an idiopathic group of intestinal disorders characterized by chronic gastrointestinal signs and a cellular infiltrate of lymphocytes, plasma cells, eosinophils, neutrophils, or histiocytes in the mucosa and submucosa. It involves chronic vomiting, weight loss, inappetence, and sometimes diarrhea.
What causes IBD in cats?
IBD arises from complex interactions between host susceptibility, mucosal immunity, and enteric microflora. A breakdown in normal mucosal immune responses to enteric bacteria is a key feature.
What are the common clinical signs of IBD in cats?
Chronic vomiting is the most common sign, followed by weight loss and inappetence. Diarrhea occurs less frequently compared to dogs with IBD.
What diagnostic tests should be conducted before diagnosing IBD in cats?
Diagnostics include history, physical exam, haematology/biochemistry, total T4, abdominal imaging, and faecal parasitology/culture to rule out extra-intestinal and infectious causes. Histological evidence of intestinal inflammation is necessary for a definitive IBD diagnosis.
What role does abdominal ultrasound play in diagnosing IBD?
Abdominal ultrasound may show diffuse intestinal thickening, altered intestinal layering, or mesenteric lymphadenopathy in severe cases, but it can be unremarkable in mild cases.
What dietary modifications are recommended for treating IBD?
Feeding novel protein diets or hydrolysed protein diets can help, especially if food sensitivities are present. Some cases require elimination diets to find a tolerable food. Added fiber may improve large intestinal diarrhea by increasing faecal consistency and supporting colonic motility.
When are corticosteroids used to treat IBD in cats?
Corticosteroids (e.g., prednisolone 1-2 mg/kg/day) are used after ruling out other causes and after trying dietary trials. They are effective in reducing mucosal inflammation, especially in moderate to severe cases.
How is metronidazole used in the treatment of IBD?
Metronidazole (10 mg/kg q 12 hours) has immunomodulatory and bactericidal effects, and it is often combined with corticosteroids in moderate to severe IBD. It can also be used as a sole agent in mild cases alongside dietary therapy. Long-term use is not recommended due to concerns of potential neoplastic transformation.
What are the potential reasons for poor response to IBD treatment in cats?
Causes include poor compliance (dietary management), severe inflammation, variants of IBD (e.g., hypereosinophilic syndrome), concurrent illness (e.g., hepatobiliary disease, renal disease), or misdiagnosis of intestinal lymphoma. Endoscopic biopsies can miss some cases of lymphoma, necessitating full-thickness biopsies in non-responsive cases.
What additional immunosuppressive agents are used for refractory IBD cases in cats?
Chlorambucil is used for refractory cases, with protocols including either continuous low-dose (2 mg every other day) or pulse high-dose (15 mg/m2 for 4 days every 3 weeks). Azathioprine is toxic to cats and is generally not recommended.
What is the recommended treatment when it is difficult to distinguish between IBD and lymphoma?
A combination of prednisolone and chlorambucil may be used for cases where it is difficult to distinguish between severe IBD and small cell lymphoma, or if biopsies have not been performed.
