The most important nutritional strategies for reducing episodes of urate urolithiasis are feeding a diet that is low in purines (not necessarily low in protein), alkalinizing, and high in moisture. Some diets that are marketed for urate prevention are very low in protein and phosphorus; these diets are more appropriate for renal disease than they are for long-term feeding of an otherwise healthy dog with urate stones. In general, purines are found in higher concentrations in animal tissue, especially metabolically active tissues such as organ meats. Purines are low in ingredients such as egg, dairy, and many plant-based ingredients, including soy. Diets based more on plant proteins than meat proteins also tend to be naturally alkalinizing.
Cole also has heart disease and dietary strategies that may be of benefit include avoiding excess sodium and supplementing with omega-3 fatty acids.
His dermatologist suspects a food allergy, but a diet elimination trial has not been completed. With his history of being exposed to a large number of proteins, finding a diet that contains novel protein and carbohydrates for use for an elimination trial, while being appropriate for his other health conditions is unlikely. Whether or not Cole has a food allergy, omega-3 fatty acids from fish oil may have benefits for reducing his allergic symptoms due to their anti-inflammatory properties.
The Clinical Nutrition Service recommended a dry hydrolyzed soy therapeutic diet that contained <100 mg/100 kcal sodium. This diet was low in purines, and also suitable for a dietary elimination trial because of the hydrolyzed proteins. Cole was supplemented with fish oil (65 mg/kg DHA + EPA) and because the diet was only available as a dry option, the owner was instructed to add 3 cups of water to each cup of food.
The owner was very compliant, and the dog was closely monitored by both the Internal Medicine and Clinical Nutrition services to ensure specific gravity was <1.020, urine pH was >7 as much as possible, and that body weight was stable. Food allergy was ruled out since the pruritus did not resolve during the diet trial, but the owner continued to work with the Dermatology Service to control his pruritus. Although food allergy was no longer an issue, the hydrolyzed soy diet was continued because it was nutritionally complete and balanced and because it met his other nutritional goals. Two years later, Cole remained stone-free, with well-controlled pruritus, and only mild progression in his heart disease.