Nutritional Management of Renal, Cardiac, and Hepatic Disease
Renal disease
Therapeutic renal diets restrict phosphorus and moderate protein to reduce uremic toxin production while maintaining adequate energy. Protein restriction should not be excessive; muscle wasting is a poor prognostic sign. Potassium supplementation is common in cats. Early institution of renal diets improves outcomes in chronic kidney disease.
Cardiac disease
The central concern is sodium restriction, titrated to disease severity. Cachexia is common and worsens prognosis; maintain caloric intake with palatable, energy-dense foods. In dogs with dilated cardiomyopathy, ensure adequate taurine and consider diet-associated DCM linked to grain-free or legume-heavy diets. Monitor for concurrent kidney disease when restricting sodium.
Hepatic disease
Avoid protein restriction unless hepatic encephalopathy is present. Provide adequate energy and high-quality protein; manage hepatic lipidosis in cats with aggressive early enteral feeding (often a feeding tube). For portosystemic shunts, use highly digestible protein and manage encephalopathy.
Traps
- Protein restriction is overused in liver disease; it worsens catabolism.
- Sodium restriction must be balanced against palatability and renal function.
- Phosphorus control matters more than protein alone in renal disease.
- Hepatic lipidosis requires prompt feeding, not starvation.
Worked example
A cat with IRIS stage 3 CKD: transition to a phosphorus-restricted renal diet, monitor potassium and muscle condition, and reassess phosphorus and creatinine every 4-8 weeks.