Chronic enteropathies are described as a group of gastrointestinal disorders characterized by gastrointestinal signs that persist for at least 2 weeks. These diagnostic designations may include a variety of disorders and populations of patients, therefore the nomenclature can be inconsistent and results in confusing information in the literature.
Also, it is important to note that nutrient profiles of diets change frequently when nutritional factors are used in the management of gastrointestinal tract disease. Canned and dry varieties of the same diet along with a variety of flavors may have variable nutrient profiles and are not to be used interchangeably.
Hydrolyzed diets: Have gone through a process where the macronutrient structure is changed to reduce or eliminate allergenic or antigenic potential. These diets usually contain a single protein source of small polypeptides to reduce antigenicity. The commercially available therapeutic hydrolyzed diets contain hydrolyzed soy, poultry or fish protein sources and such carbohydrate sources including rice, wheat and starch. If a food allergy is suspected, the choice for the protein source should be given heavy consideration during the diet selection for the patient. This type of diet is usually highly digestible when compared to the digestibility of the parent protein source and also typically have a lower fiber content.
Limited-ingredient compared to novel-protein diets: Limited-ingredient diets should provide a single carbohydrate and single protein source. When a patient has not previously been exposed to either of these ingredients, the diet is then called a novel-protein diet. Due to different factors, it is difficult to identify a novel ingredient. The authors comment that limiting the antigen load to the gastrointestinal tract could possibly benefit a patient with food intolerance too.
Fiber: Defined as complex, nondigestible carbohydrates of plant origin. Two methods to describe fiber sources include fermentability or solubility of the fiber. The intestinal microbiota allows for various degrees of fermentation; the degree of which is dependent on the fermentability inherent to that fiber source. The results of fermentation are short-chain fatty acids, water, organic compounds and acidification of the environment of the GI tract. Another way to categorize fiber is soluble or insoluble. Solubility of a fiber is its ability to disperse in water. Total dietary fiber includes all soluble and insoluble sources (crude fiber terminology provides no information regarding soluble fiber). Soluble fiber is more readily fermented which results in the production of volatile fatty acids that can benefit enterocytes and help the microbiota. Insoluble fiber is less fermentable and this can increase GI motility and passage of contents. Fiber can also act as a prebiotic.
Digestibility: This is a complicated process influenced by the patient as well as the diet ingested. Highly digestible diets are usually reported to have a total digestibility > 80% and digestibility of major macronutrients > 90%.
Fat content: Commercially available diets include a number of animal and plant fats to provide calories, essential fatty acids, fat-soluble vitamins and to enhance palatability. Veterinary therapeutic low-fat diets provide between 1.7 and 2.6 g of fat/100 kcal. They maintain adequate dietary fat for patients with chronic enteropathies that are response to a lower fat content. The authors state that the role of dietary fat in managing GI tract disease is becoming more recognized. Cats seem to have a higher tolerance for such diets with a high dietary fat content though the effect in cats with chronic enteropathies is unclear and needs further study.
Home-prepared diets: It is critical to consult with a board-certified veterinary nutritionist to ensure that the recipe is complete and balanced nutrition.
Food Responsive Disease (Chronic Enteropathy): 60% of cats with chronic enteropathy respond to nutritional management and are labeled as having FRD. Hydrolyzed diets can be valuable in treating FRD. One study in cats with small intestinal IBD that were fed a hydrolyzed soy protein diet had clinical signs resolve within 4 to 8 days. Offering the cat their former diet lead to a relapse of the GI signs and reinstituting the hydrolyzed diet resolved the clinical signs again. The authors comment that it may be beneficial to attempt another dietary approach in a patient with chronic enteropathy before ruling out FRD.
Food allergy is immunologically driven and food intolerance has no immunologic component. The most commonly recognized allergens identified in cats are beef, dairy products and fish. The clinical signs in patients with food allergies are varied though vomiting and small bowel diarrhea with concurrent skin signs are common manifestations.
Protein Losing Enteropathy / Lymphangiectasia: PLE is less common in cats. Dietary fat restriction is not considered important in cats since they appear to tolerate fat better than dogs.
Gluten Enteropathy: This disease form is not recognized in cats.
Large Bowel Disease: The authors note that there is limited information on nutritional management of colitis in cats. In one study, six cats were treated with diet alone and all six had a positive response. In the studies they evaluated, ultimately diet alone was sufficient for disease management.
In summary, chronic enteropathies can be effectively managed with diet. This form of nutritional management offers advantages over long-term administration of antimicrobials or use of immunomodulatory medications. Also, multiple dietary trials are worth considering in patients that fail to respond to initial empirical choices. Dietary modification and good patient monitoring can create a stable response to treatment.
