Safety of torasemide in healthy adult dogs administered daily for 26 weeks.

Thirty-two (16 males and 16 females) healthy young beagles were randomly divided into four groups of eight. The control group remained untreated. Torasemide (ISEMID® , Ceva Sante Animale) was orally administered, once daily, at 0.5 mg/kg from Days 1-5 then 0.25 mg/kg to Day 182, and at three times and five times this dosing regimen in two additional groups. Treated animals (predominantly at the higher dose levels) showed dryness of the oral mucosa, evidence of diuresis, decreased diet consumption, decreased bodyweight gain over the first 3 weeks, increased water consumption, increases in erythrocytes count, haemoglobin, calcium and magnesium, decrease in chloride, phosphorus, potassium and sodium, increases in urine pH, decreases in urine specific gravity and increases in serum aldosterone concentrations. Plasma concentrations of torasemide increased in a dose-dependent manner and showed no evidence of accumulation. There were also changes to electrocardiogram patterns and the macroscopic and microscopic appearance of the kidney and adrenal glands, but these changes were almost exclusively confined to the over-dosed groups. In conclusion, torasemide was found to be safe when administered to dogs at 0.25 mg/kg once daily for 26 weeks, and any changes were consistent with its known diuretic effects.