A GENETIC COMPARISON OF PITUITARY PARS INTERMEDIA DYSFUNCTION POSITIVE & NEGATIVE EQUINES AT DBH, TO AID IN THE DEVELOPMENT OF GENETIC DIAGNOSTIC PROTOCOLS.

Pituitary pars intermedia dysfunction (PPID) is the most common endocrine disorder of horses and ponies, and is a progressive neurodegenerative disease resulting from a loss of dopaminergic periventricular neurons that innervate the pars intermedia. Currently, diagnosis is made by a combination of clinical signs and multiple endocrine hormone tests. Using DNA extracted from equine hair follicles, the dopamine beta-hydroxylase gene (DBH) was studied as a candidate gene for association with PPID. Preliminary research indicates high levels of variation in all animals sampled, with no correlation to PPID, indicating further research must be conducted to determine the genes associated with this disorder, as PPID is likely to be influenced by multiple genes and the environment, much like other neurodegenerative disorders.