Chronic kidney disease (CKD) is a common, irreversible, and progressive disease in dogs and cats. In patients with CKD, mineral and bone disorders occur due to impaired kidney function. Hyperphosphatemia is known to be a prognostic factor for shorter survival time in dogs with CKD. It also can speed up the progression of the CKD and can be fatal if left untreated. Therefore, prevention and management of hyperphosphatemia may improve the prognosis of dogs and cats with CKD.