Treatment options for hyperphosphatemia in feline CKD: what's out there?

PRACTICAL RELEVANCE: Phosphorus is retained in chronic kidney disease (CKD), promoting renal secondary hyperparathyroidism and eventually resulting in hyperphosphatemia. Most agree that phosphate retention is a major contributor to the progression of CKD in many species and it is well known that hyperphosphatemia is associated with a significant mortality risk in humans with end-stage renal disease. PATIENT GROUP: Chronic kidney disease is a common ailment of geriatric cats. EVIDENCE BASE: There is evidence in cats suggesting that the use of a phosphate-restricted diet in IRIS stage 2-3 disease has a beneficial effect on clinical outcome. However, despite the fact that intestinal phosphate binders are commonly used in veterinary practice for patients with CKD, there have been few published reports focusing on the safety and efficacy of these products in veterinary medicine. No phosphorus binders are licensed as medications for dogs or cats. This article draws on data from clinical trials in humans and studies in cats to discuss treatment goals and options for phosphate retention and hyperphosphatemia in feline CKD. CLINICAL SIGNIFICANCE: With careful monitoring of serum phosphate and parathyroid hormone, and implementation of phosphate-restricted dietary management and intestinal phosphate binders, progression of CKD and the degree of hyperparathyroidism in cats may be reduced. AUDIENCE: Companion animal and feline practitioners are at the forefront in the management of CKD in cats.