Effect of sodium-glucose cotransporter 2 inhibitor canagliflozin on interstitial glucose concentration in insulin-treated diabetic dogs

BACKGROUND

The utility of sodium-glucose cotransporter 2 inhibitors (SGLT2i) has not been reported in insulin-treated diabetic dogs.

HYPOTHESIS

Canagliflozin, a PO-administered SGLT2i, decreases interstitial glucose concentration (IG) in insulin-treated diabetic dogs.

ANIMALS

Five insulin-treated diabetic dogs.

METHODS

Uncontrolled open label longitudinal study. Canagliflozin (2-4 mg/kg/day PO) was added to an unchanged insulin dose for 7 days. Fractional excretion of glucose was calculated by dividing the product of urine glucose and serum creatinine concentrations by the product of serum glucose and urine creatinine concentrations. Hypoglycemia was defined as IG <60 mg/dL.

RESULTS

Median IG in 2869 measurements obtained while dogs were treated with insulin and canagliflozin was 87 mg/dL (range, 40-500 mg/dL) and was significantly lower than median IG in 1426 measurements obtained while dogs were treated with insulin alone (212 mg/dL; range, 41-500 mg/dL; P < .001). Median fractional excretion of glucose when dogs were treated with insulin and canagliflozin was 1.1% (range, 0.9%-2.0%), significantly higher than when dogs were treated with insulin alone (0.3%; range, 0.01%-1.0%; P = .04). The frequency of hypoglycemia was higher in dogs treated with insulin and canagliflozin (544 of 2869 IG measurements, 19%) compared with the frequency of hypoglycemia in dogs treated with insulin alone (52 of 1426 IG measurements, 4%; P < .001).

CONCLUSIONS AND CLINICAL IMPORTANCE

Canagliflozin may have a role in improving glycemic control in insulin-treated diabetic dogs, but the dose of insulin should be decreased when adding canagliflozin to insulin treatment.

Renal cystadenoma in a domestic shorthair

An 11-year-old domestic shorthair was examined after an enlarged left kidney was palpated by the referring veterinarian. No abnormalities were noted on complete blood count, serum biochemical profile and total thyroxine concentration, and the urine specific gravity was 1.039. An abdominal ultrasound identified the presence of a large cystic structure on the caudal pole of the left kidney. No abnormalities of the right kidney were seen. A left ureteronephrectomy was performed, and the cat recovered uneventfully from the procedure and was discharged from the hospital 5 days after surgery. The cat remains clinically normal 16 months postoperatively. Histopathology of the removed kidney demonstrated the presence of a renal cystadenoma. This report describes the successful surgical treatment of a renal cystadenoma. Renal cystadenoma should be considered as a differential diagnosis when renomegaly is noted. To the author's knowledge, a renal cystadenoma has not been previously reported in a cat.