Dietary therapy plays such an integral role in the management of gastrointestinal (GI) diseases that it constitutes a part
of the therapeutic plan in virtually every such case. Diet can be part of the diagnostic process as well, such as using an
elimination diet in a dietary trial. It is beyond the scope of this discussion to address each disease of the GI system and
the recommended diagnostic and therapeutic approach for each. Instead, we will consider methods for obtaining an in-depth
nutritional assessment of each patient and developing an individualized nutritional plan for dogs and cats with different
categories of GI disease to optimize the success (and avoid common pitfalls) of nutritional therapy.
The Circle of Nutrition
Animal Factors-consider the patient's signalment, lifestage, current body weight and body condition (as well as any recent changes in weight
and BCS) physical exam findings, health, appetite, activity level and the environment. A detailed history of gastrointestinal
signs, and laboratory results should be included help to localize the area and extent of GI tract affected. (see table 1).
Table 1 Anatomic Localization — Small Bowel vs. Large Bowel Diarrhea
Determine whether the current diet is home prepared or commercial product(s) including the form (moist semi moist or dry).
If home prepared, obtain the recipe and amounts eaten. If the patient is fed a commercial food, examine the quality and availability
of the diet. The food should be made by a reputable manufacturer, have a nutritional adequacy statement that it has undergone
animal feeding trials for adult maintenance, have a nutrient profile matching the needs of this specific pet, and provide
adequate dietary protein. Ask how long the patient has eaten its current diet. With GI disease, owners will often have attempted
several diet changes on their own, or on the advice of staff from a pet food specialty store, their neighbour or the internet.
Asking only about the current diet can be misleading and not reflective of usual intake. If the patient has undergone recent
or frequent changes in foods, ask specifically about each diet used, (brand, flavor/type) as well as the response to each
diet, and reason for change. Make sure to ask about type and amounts of additional dietary components, treats and supplements.
Feeding Management Factors
Ask how the food is offered and how often. Is it measured and how? Is intake observed? The availability becomes especially
important in multi-pet households.
Once this assessment is complete, either a diagnostic plan is in place, or hopefully a diagnosis is pending. Sometimes, however
the decision is made to perform a diet trial in lieu of diagnostics, as part of the diagnostics or as part of the therapeutic
plan. Use your knowledge of localization of the disease, and the nutrient profile of the diet to formulation the nutritional
plan for the patient. The nutritional goals should be to 1) meet the nutrient requirements for species, and lifestage with
a complete and balanced diet 2) prevent or correct protein calorie malnutrition 3) improve or resolve clinical signs 5) correct
any underlying nutrient deficiencies (ex. cobalamin in IBD) 6) potential for targeted nutrient to modulate the disease process.