Semen, Testicular Volume, Sperm Production Efficiency, and Sexual Behavior of Stallions Treated with Trimethoprim-Sulfamethoxazole and Pyrimethamine

Sylvia J. Bedford, LV, MS and Sue M. McDonnell, PhD

    The treatment of normal breeding stallions with recommended dosages of trimethoprim-sulfamethox-azole and pyrimethamine did not affect semen quality, testicular function, or sexual behavior. There was evidence of transient musculoskeletal or neurologic deficits (30 days into treatment through 30 days after treatment) that affected copulatory form and ejaculation pattern.