Dourine is a parasitic venereal disease of equids caused by the flagellate protozoan Trypanosoma equiperdum. Previous studies used melarsomine hydrochloride, diminazene diaceturate and quinapyramine sulfate for the treatment of dourine-infected horses, however, the constant concern is that animals may improve clinically but remain carriers of the parasite. Herein, we report efficacy of quinapyramine chloride and quinapyramine sulphate (Triquinâ) against T. equiperdum infection in horses. Eight naturally-infected horses (1 male and 7 females) with lethargy, exhaustion, long sleeping periods, swelling and depigmentation of the skin of perineal region, and vaginal discharges were treated 2 or 3 times with 0.03 mg/kg bodyweight Triquin subcutaneously at 3 months intervals. Blood was collected monthly from horses, and their plasma were tested with CATT/T.evansi kit which detects circulating antibodies against surface antigens of the parasite. In addition, hematological profile and clinical data were recorded monthly for each horse. After the treatments horses were given 2 mg of dexamethasone sodium phosphate intramuscularly for 5 consecutive days for immunodepression and re-evaluated for parasites elimination confirmation with CATT/T.evansi. An obvious improvement in the health of treated horses, which was in agreement with data on CATT/T.evansi, showed efficacy of 3 Triquin treatments in 4 mares. Two mares were treated with only 2 injections as they got pregnant but got seronegative 8 months after the second injection. One male and one female horse which remained 3+ and 2+ in CATT/T.evansi were treated with 4th Triquin dose and became 1+ and negative after one month. Parasites were never detected in the blood of horses by KIN PCR thorough the study. Our result suggests therapeutic potential of repetitive Triquin treatments against dourine at an early phase i.e. prior to invasion of trypanosomes to cerebrospinal fluid. Monthly hematological, serological and clinical foll
