Objective

To describe the acid-base balance of diabetic animals with ketosis and to identify underlying mechanisms of acid-base changes using semiquantitative analysis.

Design

Retrospective study.

Setting

University teaching hospital.

Animals

Eighty-one client-owned dogs and 15 client-owned cats with diabetes and concurrent ketosis presented to a university teaching hospital.

Interventions

None.

Measurements and main results

The medical records database was searched from January 2017 through December 2021 for dogs and cats with diabetes mellitus and ketones present in urine or blood samples that also had venous blood gas and serum biochemical assays performed within 24 hours of each other. Traditional analysis identified normal acid-base status in 20% of dogs and 7% of cats. A simple metabolic acidosis with an elevated anion gap was observed in 17% of dogs and 20% of cats, and a metabolic alkalosis was present in 4% of dogs and 7% of cats. The semiquantitative approach identified metabolic acid-base disorders in all animals. One or more acidifying processes were evident in 100% of dogs and 100% of cats, 1 or more alkalotic processes in 93% of dogs and 100% of cats, concurrent alkalotic and acidotic processes in 85% of dogs and 100% of cats, and unmeasured anions in all cases.

Conclusions

Dogs and cats with diabetic ketosis can have variable and complex acid-base disorders that may be better recognized using semiquantitative analysis. Diagnostic criteria such as low pH or a high anion gap may prevent the clinical recognition of diabetic ketoacidosis.