Foundation takes a new look at an old disease: PPID
Equine pituitary pars intermedia dysfunction (PPID) is a well-known disease of horses. It’s considered the most common endocrine (gland) disorder affecting equids. Estimates suggest upwards of 15%-30% of horses over the age of 15 have PPID, and some experts believe the number might be even higher.
For many of us old enough to remember, equine Cushing’s disease, as it was known at the time, was an oddity, something unusual and uncommon. However, improved diagnostic tests, coupled with a better grasp on pituitary physiology, suggest the disease is more common than was thought just a few decades ago.
As the name suggests, PPID is a disease of the pituitary gland, a small organ located in the brain. The pituitary gland produces and stores hormones crucial to many different bodily functions, including metabolism, reproduction and growth. One of the hormones produced by the pituitary gland is adrenocorticotropic hormone (ACTH). In PPID, the pituitary gland becomes diseased and begins to produce too much ACTH. This hormone has many functions, including increasing production of cortisol. Excess cortisol in turn leads to numerous clinical signs associated with this disease, including:
- Hair coat changes
- Behavior changes
- Muscle loss
- Pot belly
- Recurrent infections
PPID can be diagnosed through specialized blood tests in combination with clinical signs. Many of the tests can be performed in the field and don’t require referral to a specialty clinic, although that occasionally is needed for some very specific tests.
PPID is treatable but not curable, and therapy is lifelong.
Because of PPID’s significant impact on horse and pony health and well-being, Morris Animal Foundation decided to make it a focus of the Foundation’s latest call for equid health proposals.
“PPID is an important disease to study because it’s so common,” said Dr. Nicola Menzies-Gow, Professor in Equine Medicine at the Royal Veterinary College, United Kingdom. “And PPID causes clinical signs which can have a significant impact on the affected animal’s quality of life.”
Although the equine medical community has recognized PPID for decades, many unanswered questions remain. This is where the Foundation stepped in and reached out to veterinary scientists to submit projects aimed at tackling PPID.
“There are still a lot of big questions about PPID that need answers,” said Dr. Menzies-Gow. “For example, we don’t know what actually causes PPID. We also need a diagnostic test that can detect the disease with 100% accuracy in all animals. And we need more information about how our current treatment affects the risk of laminitis.”
Dr. Menzies-Gow is one of the equine medicine experts who recently reviewed project proposals submitted to Morris Animal Foundation. Each proposal is carefully scrutinized and only the very best projects are recommended for funding.
Several excellent PPID-focused proposals from researchers around the world were reviewed. Projects recommended for funding include a unique study that hopes to harness the power of artificial intelligence (AI) in the early diagnosis of PPID. Another study will revisit the use of an older drug, cyproheptadine, in the treatment of PPID.
It’s clear that PPID has risen from oddity to important disease of equids, and that it has a larger impact on health and welfare than previously suspected. Morris Animal Foundation is excited to help improve the quality of life for thousands of horses and ponies through our new grants!
[Read more: 30 is the New 20 for Senior Horses]