Studies in dogs and cats dosed with trimethoprim and sulphadiazine

Serum level studies in cats and dogs dosed with 30 mg per kg per day of either oral or injectable formulations of a 1:5 trimethoprim/sulphadiazine combination showed good absorption by both routes of administration. Toxicity tests with the products demonstrated a high margin of safety in dogs given this dose level; the margin of safety in cats was lower but still adequate. The high success rate in clinical trials against a wide range of bacterial infections confirmed the predictions from the serum level results that a dose rate of 30 mg per kg per day orally or parentally, would be therapeutically efficacious in both species.