Clinical and laboratory characterization of dogs in different stages of chronic kidney disease and the importance of hyperphosphatemia

Chronic kidney disease (CKD) is a progressive and degenerative disorder
that mainly affects elderly dogs. There is no cure for CKD, and since most
patients are diagnosed late, when treatment will be ineffective, survival time
is short. In order to standardize procedures for the detection and treatment of
CKD, the International Renal Interest Society (IRIS) proposed a classification
system based on serum creatinine concentration. Hyperphosphatemia is one of the
major complications of CKD, which is correlated with high mortality in human
patients with this disease. The present study followed 65 dogs with CKD and an
average age greater than seven years. The mortality rate was 55%. According to
the IRIS staging system of CKD for dogs, 6.2% were in stage 1, 13.8% in stage
2, 38.5% in stage 3, and 41.5% in stage 4 when the study beganAs their condition worsened, in most
animals proteinuria and blood pressure increased, but urine density decreased.
Most animals in the more severe stages of CKD presented proteinuria, arterial
hypertension, and low urinary density. Hyperphosphatemia was associated with
high rates of mortality, hypoalbuminemia, hypertension, proteinuria, and disease
progression, and mainly occurred in IRIS stages 3 and 4. The use of a renal
diet contributed to the control of hyperphosphatemia and increased the survival
of dogs with CKD.