Treatment And Follow Up Of Renal Disease In Dogs And Cats

Renal disease is one of the most common diseases of senior dogs and cats. It is often only diagnosed when >66% of renal function is lost. Acute renal failure (ARF) is characterized by anorexia/dysrexia, vomiting, weight loss, loss of muscle mass, and dehydration. Correction of fluid and electrolyte imbalances is the first aim of treatment. When the patient is hemodynamically stable it is important to start nutritional support. The first aim of nutritional support in the hospitalized ARF patient is to correct imbalances and deficiencies, to minimize the catabolic effects on muscle, and to support recovery. As most patients with ARF are nauseous it is important not to start feeding a diet which you want to feed on the long term, as food aversion is common, especially in cats. As patients with ARF are in a negative energy balance and a negative protein balance, it is not recommended to start feeding a low protein diet. A recovery type diet (i.e. high protein, high fat) is the first choice product for patients with ARF. These diets usually are designed to also fit through nasogastric tubes and can also be force fed by a syringe. When the patient is consuming sufficient quantities to meet resting energy requirements, a transition to its normal diet can be made. The renal diet, which has spectacular effects on the long term (i.e. increases life expectancy 3-fold, and reducing risk of uremic crises with 75%) ^(1,2,3) , should only be fed to patients with chronic renal failure that have normal appetite and are totally recovered from ARF. Renal diets should be gradually introduced over a 1 week period (first 2 days 25% renal diet, 75% current food, 2 days 50-50, and 2 days 75-25). After 2 weeks on the renal diet, the effect can be measured by evaluating the magnitude of proteinuria, urea, creatinine. The goal is to reduce uremia and proteinuria. If this is not achieved, more protein restricted renal diets may be necessary. Also a good diet history should be performed. Renal diets can have spectacular effects, but only when they are eaten in sufficient amounts. If this is not the case, feed intake is more important than diet. Homemade diets, prescribed by a veterinary nutritionist can also be helpful for pet owners that are motivated, and if no commercial renal diet is being eaten by the pet.

References

1. Finco DR, Brown SA, Crowell WA, Duncan RJ, Barsanti JA, Bennett SE. Effects of dietary phosphorus and protein in dogs with chronic renal failure. Am J Vet Res. 1992 Dec;53(12):2264-71.
2. Brown SA, Brown CA, Crowell WA, Barsanti JA, Allen T, Cowell C, Finco DR. Beneficial effects of chronic administration of dietary omega-3 polyunsaturated fatty acids in dogs with renal insufficiency. J Lab Clin Med. 1998 May;131(5):447-55.
3. Plantinga EA, Everts H, Kastelein AM, Beynen AC. Retrospective study of the survival of cats with acquired chronic renal insufficiency offered different commercial diets. Vet Rec. 2005 Aug 13;157(7):185-7.