Ovarian hyperstimulation syndrome in a bitch caused by recombinant human chorionic gonadotropin treatment of suspected luteal insufficiency – a case report

Abstract

Two bitches with a history of hypoluteoidism were treated by recombinant human chorionic gonadotropin (r-hCG) in repeated doses during early dioestrus. The level of progesterone increased, but the therapy led to hyperstimulation of the ovaries which resulted in ovarian hyperstimulation syndrome (OHSS), with subsequent development of oestrogen toxicity. This is the first case documenting OHSS in a canine after administration of r-hCG. Although manifested during dioestrus in our case report, the occurrence of OHSS is associated with similar administration of r-hCG to women. The described use of r-hCG is not appropriate for luteal insufficiency treatment, but seems to have a place in assisted reproduction technology because of its surprising effects. Further research of luteotrophic factors in bitches is warranted because of these unpredictable results. Lower doses and frequency of administration need to be considered for a better outcome.