Identifying hydric, electrolyte and acid-base imbalances in dogs with Chronical Kidney Disease (CKD)

ABSTRACT This study aimed to characterize water, electrolyte and acid-base imbalances and evaluate traditional and quantitative approaches in dogs with renal azotemia. We evaluated 34 dogs with clinical and laboratory diagnosis of chronic kidney disease (CKD) and ten healthy dogs were evaluated. Venous blood gas analysis was performed during the patient's initial care before any therapeutic measure was instituted. The parameters measured were pH, pCO2, HCO3 -, BE (ecf), Na+, K+, Cl-, iCa2+, glucose, lactate, phosphate, and albumin. The mean, median and standard deviation of all analyzed parameters were calculated for sick and healthy dogs. 52.9% (18/34) of animals did not show apparent dehydration. The most common electrolyte changes were hyperkalemia 76.4% (26/34), hypochloremia 58.8% (20/34) and hyponatremia (52.9%) (18/34). Metabolic acidosis was the most common acid-base disorder in both approaches. Using the traditional approach, 70.5% (24/34) presented metabolic acidosis due to reduced HCO3 - concentration. When considering the AG value, 61.76% (21/34) of the dogs showed an increase in AG or acidosis due to an increase in unmeasured anions. While using the quantitative approach, metabolic acidosis was identified by evaluating the reduction in SIG in 82.3% (28/34) of dogs and 14.7% (5/34) with hyperchloremic acidosis by reducing SID. Only in this approach, metabolic alkalosis was detected due to a reduction in Atot 55.8% (19/34) and an increase in SID due to hypochloremic alkalosis in 35.3% (12/34). It is concluded that the most common imbalances found in these dogs with nephropathy were hyperkalemia, hypochloremia and metabolic acidosis due to an increase in unmeasurable anions and a greater number of acid-base disorders were identified by the quantitative approach.