Diets for Pets With Gastrointestinal Disease

There is not one single "best diet" for managing pets with gastrointestinal (GI) problems because numerous diseases affect the GI system and each may require different dietary management. It is important that you understand the nature and severity of your pet's GI condition before selecting a suitable diet.

Ask your veterinarian what specific GI disease is present—adverse food reaction, food allergy, fiber-responsive diarrhea, inflammatory bowel disease, colitis, or protein-losing disease. What area of the GI tract is affected—stomach, small intestine, colon? Does your pet have any other health issues that may influence the diet choice—kidney disease, liver problems?

In general, an ideal gastrointestinal diet is a "low residue" type of pet food with the following characteristics:

• High digestibility. Digestibility is a measure of how readily the nutrients in a food are broken down and absorbed into the body. If a pet with GI disease is fed a food with low digestibility many of their signs, such as diarrhea, will become worse. Most commercially available pet foods have digestibility ranging from 70 to 90%. This information is almost never available on a pet food label and a quick phone call to the company can usually provide this information. Ideally pets with GI disease would eat a diet that has at least 85-90% digestibility to help minimize their signs.
• Moderate fat content. Higher fat diets tend to slow stomach emptying time, increase the risk for acid reflux, vomiting and diarrhea. Cats with GI disease are much more tolerant of fat than dogs. In general, a GI friendly diet is usually low to moderate in fat levels (15-20% dry matter for cats and 6-15% dry matter in dogs).
• High protein content. High-quality, highly digestible protein sources have many positive effects on GI function and a high protein diet is recommended for most pets with GI conditions. Many pets that experience vomiting or diarrhea after eating a food are incorrectly diagnosed with "food allergies" to the protein components of the food (such as chicken, beef, eggs, etc.) However, true food allergies are quite uncommon and many times these adverse GI reactions are actually signs of intolerance to a poorly digestible protein source, high levels of fat or to the additives and preservatives in a food. If this sounds like your pet, consider choosing a more highly digestible, lower fat food without synthetic additives to address the possibility of this type of food intolerance. If your pet still experiences problems, it may then be reasonable to consider a novel protein food—meaning a protein source that your pet has never eaten such as venison, lamb, duck, etc.
• "Good GI carbohydrate" choices. Cats with GI disease usually feel best when not fed carbohydrates due to their unique metabolism as strict carnivores and their reduced ability to handle a carbohydrate load. For dogs, while carbohydrate levels should never be excessive, certain carbs that are highly digestible can be beneficial for GI conditions. White rice can be an excellent choice because it is gluten-free, highly digestible and not as likely to cause an immune response. Potato varieties and tapioca are also highly digestible sources of carbs that can be considered for dogs with GI disease.
• Low fiber levels. The best choice for most GI conditions is a low level of dietary fiber or other poorly digestible carbohydrates (often called "fillers"). Colitis and other conditions affecting the large bowel (constipation, etc.) are exceptions to this recommendation and additional information is found below.
• Dairy (lactose) free. Pets lose the ability to properly digest dairy products with age as well as when affected with GI conditions and lactose-containing products can worsen gas, diarrhea and bloating.
• Supplemented with Omega 3 fatty acids. Fatty acids have many proven beneficial anti-inflammatory properties and may help reduce inflammation in the GI system.
• Contains prebiotics and probiotics to enhance GI health. Prebiotics are specialized forms of fiber that, when eaten, stimulate the growth and function of healthy or "good" bacteria in the intestine. Common prebiotics added to pet food include inulin and FOS (fructo-oligosaccharides). Probiotics are live "good" bacteria that when ingested by pets help to restore bacterial balance within the intestine. Common probiotics added to pet food include Lactobacillus, Bifidobacterium and Enterococcus. You can provide prebiotics and probiotics as a supplement if your pet's food doesn't contain these ingredients.
• Contains no synthetic food additives. Avoid diets with artificial preservatives, colors/dyes, flavors, etc. as these may stimulate adverse reactions.

Other considerations depending on the type of GI disease your pet has:

• Novel protein and novel carbohydrate source if a true food allergy is suspected.
• Fiber. The addition of fiber can help improve stool quality in pets with constipation or colitis (urgency, straining, mucusy or bloody diarrhea or soft stools). Fibers are either soluble or insoluble and often an addition of a mix of these fibers is best. Soluble fibers help increase the water content of the feces and may help ease passage of stool. Insoluble fibers are often used to improve the quality of soft stool or to help stimulate the motility of the colon (by providing additional fecal bulk) in cases of constipation. There is a bit of trial and error to determine what type of fiber will work best for a pet. Examples of soluble fiber commonly included in pet food include FOS (fructo-oligosaccharides), pectins, beet pulp, psyllium (e.g. Metamucil), oats, barley, guar gum, fruits, root vegetables, peas, etc. Sources of insoluble fiber often included in pet food are cellulose and methylcellulose. Other natural foods that offer insoluble fiber include most cereal fibers (e.g. wheat and rye fibers), potato or other vegetable skins, etc.
• Homemade diet. A homemade diet with a single protein and a single, highly digestible carbohydrate source (e.g. chicken and rice, turkey and potato, etc.) can be very effective in pets with GI disease because they are highly digestible and have no artificial ingredients—so adverse reactions are minimized. If your pet responds well to this type of diet, you can continue feeding a homemade food but it is necessary to work with your veterinarian or a veterinary nutritionist to balance this food with vitamins and minerals to prevent nutritional deficiencies.