Nutritional Strategies for Inflammatory Bowel Disease
Inflammatory Bowel Diseases, or IBD, is the most common cause of chronic vomiting and diarrhea in cats and dogs. In addition to the discomfort caused by the symptoms, pets with IBD also suffer significant nutrient deficiencies. Although this condition is without a cure, nutritional strategies may help control the symptoms and potentially decrease the dosage of drugs needed for this condition.
What is IBD?
IBD is an idiopathic condition. In med-speak that means we have no real clue to its cause, so we are left with speculations. The condition is characterized by an abnormal immune response in the innermost layer of the stomach and intestines, called the mucosal lining. The mucosal lining is responsible for regulating the digestion and absorption of food. The abnormal "invasion" of infection fighting white blood cells interferes with those functions, resulting in the symptoms of vomiting and/or diarrhea, depending on the location of the condition in the gut. Pets with lesions in the stomach or upper intestines typically vomit, while those with lower bowel involvement exhibit chronic diarrhea.
It is speculated that the disease is an over-reaction of the immune system to the normal intestinal bacteria. This is supported by the fact that the administration of antibiotics directed at gut bacteria is often helpful. Abnormal immune response to food proteins is also speculated. Improvement with limited protein diets or elimination diets supports this theory.
As the condition progresses, antibiotics and dietary changes become less effective and these pets are treated with corticosteroids, prednisone, or prednisolone, and in retractable cases chemotherapeutic drugs like azathioprine.
Nutritional Strategies for IBD in Pets
Disruption of the digestive and absorption processes by the exaggerated immune response causes multiple nutritional deficiencies.
Many of these pets experience significant weight loss due to the inability to absorb adequate calories and protein. The lack of adequate absorption of magnesium and iron can result in decreased muscle and nerve function and anemia. Zinc deficiency exacerbates diarrhea. Generally the gut bacteria produce adequate amounts of vitamins B12 and K. For pets with IBD this is not the case. B12 deficiency can enhance the level of anemia and K deficiency can prolong blood clotting function and promote bleeding and blood loss in IBD patients.
Increasing the protein levels in diets and supplementing with multiple vitamin and mineral supplements may help these patients. The protein source should be novel (venison, duck, salmon, etc.) or hydrolyzed. Injectable vitamin and mineral supplements may also be necessary for pets with advanced disease.
IBD patients also exhibit antioxidant deficiencies. Free radical production increases with inflammation, and deficiencies of the vitamins A, E, and C, and antioxidant defensive minerals zinc, manganese, and copper accelerate oxidative damage. Supplementation with antioxidants has shown to be effective in reducing intestinal damage.
The use of pre- and probiotics to treat IBD has received much attention. Results are conflicting but consensus is that quality pre-biotics increase the population of beneficial gut bacteria that may aid IBD patients. The amount of beneficial bacteria found in probiotics has yet to be defined for IBD patients. Veterinary products are thought to be low quality, so human products may be a better supplement choice.
Increased levels of omega-3 fatty acids in the diet can decrease destructive inflammatory responses and have shown to be effective in humans. The benefit has yet to be proven in the IBD of pets and there is presently no established dosage of fish oil for these patients. I, however, continue to treat these patients with fish oil.
Despite mostly anecdotal evidence for dietary manipulation to treat IBD, I expect greater nutritional interventions strategies as more research is conducted.
Dr. Ken Tudor