Low Libido or Sperm Production
Low libido or sperm production can not be altered by administering testosterone. In fact, exogenous testosterone will decrease sperm production by decreasing intratesticular testosterone. This effect is also seen in males taking anabolic steroids (athletes or race horses).
Unlike the mare, hCG cannot be given long enough to cause an effect on testosterone since it causes the production of anti-hCG antibodies in the stallion.
GnRH can be used to increase libido or sperm production but must be given in pulses to be effective. This is usually a last resort and only used if the stallion is valuable enough to warrant the large cost of this treatment.
