Reproductive effects of equine endocrine disease

Abstract

Endocrine disease is very common in domestic horses and ponies and has become even more so as members of these populations are currently living relatively longer. Older animals are now often successfully fulfilling their intended use (competition, pleasure riding and reproduction) well into their third decade. Therefore, managing influence of endocrine diseases (many of which increase in frequency with age) on fertility and reproductive outcomes will likely be more important for veterinary practitioners in the future. Relatively little is known about specific effects of equine metabolic syndrome and pituitary pars intermedia dysfunction on reproductive function in horses, although preliminary information describing some effects on fertility, ovulation efficiency, implantation, duration of pregnancy and lactation have been published. Further work characterizing these influences will ideally lead to establishment of concrete guidelines and best practices to optimally manage older breeding animals affected by endocrine disease.