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 25-28 September, 2018 | Singapore
diarrhea of more than 3 weeks’ duration. Mild CE may cause intermittent clinical signs, whereas progressive and severe clinical signs are common in severe cases. Poor body condition with poor hair coat is frequent with severe disease. Some animals may regularly vomit and dehydration is possible. Thickened small intestinal loops may occasionally be palpated. Animals may show pain or discomfort on abdominal palpation. Ascites, hydrothorax and peripheral edema may occur in case of significant protein loss (PLE).
Diagnosis of CE consists in an elimination process.
The aim is to rule out other diseases of known etiology that may cause similar clinical signs: fecal flotation
and Giardia antigen test should be performed in all dogs. Alternately, empiric parasiticide treatment can be administered (e.g. fenbendazole 50 mg/kg q24h for 3-5 days). Subsequently, the diagnostic process is different for dogs with mild clinical signs and no evidence of systemic complication such as hypoproteinemia, and for dogs that are more severely affected.
Dogs with mild to moderate disease can undergo a treatment trial with a novel protein or hydrolyzed peptide diet, while severely affected dogs showing significant systemic repercussions of their intestinal disease should be evaluated more thoroughly with collection of a minimal database including CBC, serum biochemistry and urinalysis. Presence of hypoalbuminemia, often accompanied by hypoglobulinemia, suggests PLE. Sensitivity of abdominal ultrasound is intermediate, and scans may be normal or show focal or diffuse loss of wall layering, presence of mucosal striations or spicules, wall thickening, enlarged and/or hypoechoic mesenteric lymph nodes. If lesions are present, localization to a specific intestinal segment may be helpful.
Procurement of biopsy samples with upper GI endoscopy or exploratory celiotomy is necessary to further evaluate disease severity in dogs undergoing an in-depth
work up. Each method offers different advantages
and drawbacks. Biopsy specimen of adequate quality and quantity are required for accurate interpretation
by pathologists. The most important justification for histology is to rule out a neoplastic infiltrate. However,
it is also useful to evaluate the magnitude of intestinal mucosal inflammation based on the severity and type
of the infiltrate and on the severity of the architectural mucosal changes. Current scoring systems are based
on results from a WSAVA working group, and take both architectural and inflammatory mucosal changes into account. Inflammatory infiltration may be of varying severity and consist of lymphocytes and plasma cells (lymphoplasmacytic enteritis), eosinophils, neutrophils or macrophages or combinations thereof. Examples of small intestinal mucosal architectural changes include villus stunting, surface epithelial injury, crypt distension, lacteal
dilation, and mucosal fibrosis.
General differentials include intestinal parasitic diseases, bacterial enteritis, fungal enteritis, chronic intestinal foreign body, and diseases originating outside the
GI tract such as chronic kidney disease, chronic liver disease, chronic pancreatitis, exocrine pancreatic insufficiency, and atypical hypoadrenocorticism.
In most instances, the goal of treatment is to manage the clinical signs. Full recovery may be possible in mild cases.
After endoparasites have been ruled out (see above), the standard approach for a dog with mild to moderate chronic recurrent diarrhea of unknown origin without significant systemic repercussions is to initiate a food trial with a novel protein or hydrolyzed peptide diet.
It is important to collect a detailed dietary history in order to identify the best-suited diet which may be different for each animal. At this time, many clinicians prefer hydrolyzed diets to novel protein diets to treat their patients with diet-responsive CE, although there
is no evidence to support their superiority. A thorough discussion about the implementation of the dietary
trial with the animal’s owners is an indispensable pre- requisite. During the trial, the dog should not receive any other food or treats than the prescribed diet. All dogs with diet-responsive CE show at least a partial response within 10 to 14 days. In dogs with partial or complete response, the dietary trial should be pursued for several months. There does not appear to be any benefit in adding probiotics to the treatment, although the studies published to date included only small numbers of dogs.
In dogs that do not respond to the elimination diet,
the next step may consist of another treatment trial
with another novel protein or hydrolyzed peptide diet. Antimicrobials may also be used in conjunction with
the new diet. Small intestinal dysbiosis (change in the composition of the intestinal microbiota) occurs in
most dogs with IBD. Young large breed dogs with CE (particularly but not exclusively German Shepherd Dogs) respond to prolonged treatment with antimicrobials such as tylosin (20 mg/kg PO BID) or metronidazole (10-15 mg/ kg PO BID). This may result from an inability of these dogs’ immune system to interact adequately with their intestinal microbiota. Clinical experience accumulated over the past decades indicates that prolonged treatment (4 to 8 weeks) is necessary, and that relapses are common. In refractory cases, and in dogs with severe disease and evidence of systemic involvement a more thorough work up with acquisition of a minimal database should be initiated (see diagnosis above).
Dietary management is also an essential part of the

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