Imipramine-induced erection, masturbation, and ejaculation in male horses.

This study investigates the effects of imipramine hydrochloride, a medication typically used for depression and other mood disorders, on sexual behavior in male horses. Notably, the drug induced frequent erection and masturbation in the studied horses, even in a nonsexual context, and helped a 5-year-old stallion with sexual dysfunction to ejaculate.

Introduction and Methodology

• The researchers wanted to explore the effects of imipramine hydrochloride on male horses. Imipramine is an antidepressant which in this study was observed to stimulate erection and ejaculation.
• They administered the drug to five horses of different backgrounds: one sexually experienced stallion, two mature breeding stallions, one 5-year-old stallion with erection and ejaculatory dysfunction, and one long-term castrated horse.
• The administration was carried two-fold: orally (100 to 600 mg, twice daily) and intravenous injections (50 to 1000 mg).

Findings

• The horses, regardless of their age or sexual maturity, typically experienced erection approximately 10 minutes after the administration of the drug, maintaining this state for 1 to 2 hours with occasional masturbation.
• Two of the stallions even ejaculated while masturbating.
• At higher doses, mild side effects such as ataxia (loss of control of body movements) and drowsiness were observed, though the horses still responded to sensory stimuli.
• The horses would frequently stop their erection and masturbation upon engagement in barn activities or the approach of the handler, indicating the potential for inhibitory control of the erection at the cortical level.
• When tested in a sexual context, the two mature stallions could breed normally even after having received the treatment.
• The 5-year-old stallion, which had shown an inability to ejaculate over several months of breeding attempts, was able to spontaneously ejaculate after the intravenous imipramine treatment.
• Surprisingly, even the long-term castrated horse exhibited erection and masturbation after receiving the imipramine treatment intravenously, suggesting that the effects of imipramine are independent of testosterone levels.

Conclusion

• The research concluded that imipramine hydrochloride could stimulate sexual behaviors in male horses, even following castration.
• Furthermore, it led to increased erection, masturbation, and even ejaculation in some cases, shedding important light on potential treatments for equine sexual dysfunctions.