Clinical Usage of GnRH Agonists in Small Animal Reproduction: A Review

Abstract

Gonadotropin releasing hormone agonists have a variety of effects on the urogenital system as well as on behavior in dogs and cats. Although their official indications are limited to controlling fertility, libido and aggressiveness in male dogs, current available information indicates that their use is effective also in inducing estrus in females, blocking cyclicity in queens, preventing male cats from roaming and urine marking as well eliminating the typical “tomcat odor” from their urine. The blocking action on cyclicity of bitches is accompanied by side effects (prolonged heat, increased risk of pyometra) which make this use not currently advisable in the dog, particularly in older females. There is evidence that GnRH agonists can be at least be partially effective in treating post-spaying urinary incontinence in the bitch. Other clinical applications which await confirmation include prevention of mammary tumor metastatic disease, treatment of androgen dependent diseases (benign prostatic hypertrophy, perianal gland adenomas) or treatment of azoospermia in dogs. Side effects of GnRH agonists have been reported in humans but not in small animals, perhaps due to their recent use and shorter life expectancy of dogs and cats. [...]