Old horses and old people suffer similar muscle loss and immune deficiencies, and a researcher at Oklahoma State University’s Center for Veterinary Health Services, hopes her work might help both. Dianne McFarlane, assistant professor of physiological sciences at the Center for Veterinary Health Services at Oklahoma State University, is investigating the similarities between Cushing’s disease in horses, also known as Pituitary Pars Intermedia Dysfunction, or PPID, and Parkinson’s disease in humans, according to an article on NewsOK.com.

McFarlane is also looking for horses to include in the study. Horses nearing 15 to 20 years of age or older that have not shed out well in the spring for the past one or two years are possibly developing ECD/PPID. Additional signs can include increased water consumption and urination, loss of muscle over the top line, and possibly concurrent development of abnormal fat deposits, such as crested neck and/or a bulge of fat over each eye. Another sign is unexplained laminitis (founder) and recurrent or chronic infections. If one or more of these signs is noted in an aged horse, then the horse may be a candidate for the study. To be included in this study, horses should not have been treated with medications or dietary supplements recommended for ECD/PPID within 60 days of study pergolide treatment initiation.

"We are interested in understanding the disease for the benefit of horses, but also it may provide some understanding for what goes on in humans that have degenerative diseases,” she said.

McFarlane notes that there are many differences between human Parkinson’s disease and PPID in horses.

However, she also says that both diseases affect the same kind of dopamine-producing neurons, and both problems appear in old age. "It does appear animals have some of the same basic factors contributing to degeneration,” she said.

McFarlane’s research has produced its first wave of data, which was recently published. The research is expected to continue for at least another four years.