Dietary Related Gastrointestinal Disorder in Dogs

Dietary related gastrointestinal disorders can be described as adverse reactions to foods that result in the onset of gastrointestinal symptoms, most notably vomiting and diarrhea. They may be caused by an abnormal or exuberant immune response to a component of the food (food allergy, food hypersensitivity), or they can occur independent of any immune system involvement (food intolerance).

Predisposing factors include the presence of any previous or current gastrointestinal disorder, young animals less than one year of age, and any concurrent allergic disorders. Both sexes are equally susceptible. Immune deficiencies predisposing to food allergy and hypersensitivity have been documented in some German shepherds and shar-peis; some Irish setters have a well-described hypersensitivity to gluten.

Food allergies, hypersensitivities, and intolerances can lead to clinical symptoms involving both the skin and the gastrointestinal tract. 

What to Watch For

Diarrhea

Vomiting

Intermittent abdominal pain

Diagnosis

Dietary elimination trials, followed by challenge. A commercial or homemade diet consisting of a novel, highly digestible protein is fed for two to four weeks, and the animal's response is noted. If the animal markedly improves, the previous diet is then offered. The return of clinical signs usually after 3 to 7 days of feeding this initial diet confirms the diagnosis.

Intradermal skin testing. Unlike skin testing for inhalant allergies, skin testing for food allergy is believed to be unreliable.

Radioallergosorbent tests (RAST) and enzyme-linked immunosorbent assays (ELISAs). These are blood tests that detect antibodies against various food components. They are believed to be unreliable in the diagnosis of food allergy or intolerance.

Treatment

Feeding a diet that does not cause an adverse reaction – once a protein source is identified that does not trigger an adverse reaction, that diet, or another diet with the same main protein source is fed thereafter.

Home Care and Prevention

Feed specialized diet as prescribed or avoid the foods that caused the illness. There are no specific measures to prevent the initial onset of a food allergy or intolerance; however, feeding the prescribed diet helps prevent future bouts of dietary related gastrointestinal disturbance. Avoid feeding your pet table scraps to reduce the incidence of gastrointestinal upset.