Managing chronic enteropathies in dogs (Sponsored by Nestle Purina)
Part of the 2009 Nestlé Purina Veterinary Symposium publication
May 01, 2009
CUSTOM VETERINARY MEDIA
Managing chronic enteropathies in dogs
Investigation of chronic small bowel diarrhea
After the exclusion of infectious and parasitic agents, non-GI disorders, exocrine pancreatic insufficiency, and intestinal structural abnormalities requiring surgery, the most common group of intestinal conditions associated with chronic small bowel diarrhea are idiopathic inflammatory bowel disease (IBD), diet-responsive enteropathy, antibiotic-responsive enteropathy, and lymphangiectasia.
The diagnostic approach to this group of patients is usually determined by the severity of clinical signs and the presence or absence of hypoalbuminemia, intestinal thickening, or mesenteric lymphadenopathy. In patients with any of these abnormalities, intestinal biopsy is required to define the cause (e.g., IBD, lymphangiectasia, lymphoma) and to optimize therapy. Controlled studies have shown that hypoalbuminemia is associated with a poor outcome in dogs with chronic enteropathy.1 , 2 Evaluation of hemostatic function is recommended to determine if hypo- or hyper-coagulability have arisen as a consequence of enteric protein loss.
The clinical severity of intestinal disease can be quantified by determining the canine IBD activity index (CIBDAI) through evaluation of attitude, activity, appetite, vomiting, stool consistency, stool frequency, and weight loss.3 Measurement of serum C-reactive protein (CRP) has been shown to correlate with CIBDAI and implies that severe clinical disease is accompanied by a systemic inflammatory response.3 Measurement of CIBDAI or CRP can also serve as a baseline for determining the response to treatment.
In stable patients with chronic diarrhea (i.e., good attitude, appetite, mild weight loss, normal serum proteins, and no intestinal thickening or lymphadenopathy), measurement of serum cobalamin and folate help evaluate disease severity, aid in localization of intestinal disease, and determine if supplementation is required. Low-serum cobalamin concentration (< 200ng/L) has also been associated with a negative prognosis.2 Intestinal biopsy is indicated in dogs with low serum cobalamin concentrations to determine the nature of the intestinal disease. In stable patients with chronic diarrhea and normal serum cobalamin concentrations, the client can be given the option of empirical treatment (see below). Failure to respond to empirical therapy or worsening of disease is an indication for intestinal biopsy.