A serum calcium-phosphorus (sCaPP) product was assessed for prediction of survival in dogs affected with chronic kidney disease (CKD). Dogs (N = 150) were retrospectively studied and followed up to determine their lifespan using 25 healthy dogs as controls. Blood and urine analyses were performed and blood pressure was measured. The dogs were divided into groups according to sCaPP (higher or lower than 70 mg2/dL2) and International Renal Interest Society (IRIS) stage (IRIS 1-4). Shorter survival was observed with sCaPP > 70 mg2/dL2 compared to dogs with sCaPP < 70 mg2/dL2 [45.48 days (range: 5.8 to 149 days) versus 505.40 days (range: 113.31 to 539.52 days), mean (95% confidence interval); P ≤ 0.001 respectively]. Similarly, dogs with advanced IRIS stages showed higher levels of sCaPP [mean (95% confidence interval) in mg2/dL2; IRIS 1: 42.83 (range: 29.58 to 62.10); IRIS 2: 63.18 (range: 46.34 to 90.09); IRIS 3: 95.57 (range: 88.34 to 127.19); IRIS 4: 130.38 (range: 125.16 to 153.52)], accompanied by lower survival rates. Therefore, sCaPP could represent a valuable tool in the prognosis of canine CKD.