by Jennifer Showalter
LEXINGTON, VA — Advancements in nutrition, veterinary care, and other practices are allowing horses and ponies to live longer than they once did. As horses and ponies age, they become more at risk for PPID, or what is often referred to as Equine Cushing’s disease. With this being a concern for many horse owners, 55 people from Roanoke to Harrisonburg recently traveled to Lexington for an educational seminar and dinner. Mountain View Equine Hospital, Blue Ridge Equine Clinic, and Westwood Animal Hospital proudly welcomed Dr. Bob Stenborn, D.V.M., senior veterinarian with Boehringer Ingelheim Vetmedica Inc., to the Shenandoah Valley to share his knowledge on identifying and treating PPID.
Stenborn informed the audience that PPID is the most common endocrine disorder in horses and ponies that are 15 years old and older. It is estimated that 15 to 30 percent of horses over the age of 15 years suffer from PPID. PPID, or Cushing’s Disease, in horses is not exactly the same as Cushing’s Disease in dogs and humans. Ponies are more acceptable as are certain breeds of horses such as Morgans, Pasos, Arabs, Quarter Horses, and Saddlebreds. Stenborn pointed out that the disease is gender neutral for the most part, but geldings are slightly more at risk. Healthy horses have ample dopamine levels were as horses with PPID lack dopamine and have a pituitary gland two to six times larger than its’ normal size.
Early clinical signs of PPID include laminitis, change in attitude/lethargy, decrease athletic performance, change in body conformation, excessive hair growth on specific areas of the body, delayed or loss of the ability to shed, and a cresty neck and/or fatty deposits. More advanced clinical signs may include recurrent infections, laminitis, change in attitude/lethargy, excessive hair growth over the entire body, delayed or loss of shedding, rounded abdomen or pot belly, skeletal muscle atrophy, abnormal sweating, excessive urination, excessive thirsts, absent reproductive cycle, hyperglycemia, neurologic deficit, and a cresty neck and/or fatty deposits.
Stenborn noted that 30 to 70 percent of PPID cases suffer from laminitis, which is one of the main reasons for euthanasia. There is no text book case when it comes to PPID, but abnormal hair coats and laminitis are the top two most common signs. “PPID doesn’t kill. It’s all the other things that cause a snowballing affect,” said Stenborn.
Horses and ponies with PPID tend to have high levels of cortisol which is an insulin antagonist that leads to laminitis. Stenborn stressed that it is important for insulin levels to be known so things can be kept in as close of check as possible.
Stenborn made clear that PPID horses are often fed too well which only intensifies their complications. “One of the problems with these horses is we feed them too much. We really should be feeding them crummy hay,” said Stenborn. Feeding programs need to change to include nonstructural carbohydrates. He recommended having hay tested to know what is being fed, using grazing muzzles, and only allowing three to four hours of pasture access each day. When decreasing carbohydrates in the diet, Stenborn told the audience they may want to consider supplementing with vitamins, minerals, electrolytes, and probiotics. “The nutrition part isn’t an easy part, but it is important,” said Stenborn.
While there is not a cure for PPID, pergolide mesylate has been used for years by veterinarians to manage the clinical signs associated with PPID. Veterinarians prescribed Permax®, a human drug for Parkinson’s Disease, for decades to treat the clinical signs, but in 2007, the manufacturer withdrew the drug from the market. Veterinarians were left without any FDA-approved form of pergolide to use.
In 2011, the FDA approved Prascend® as a product specifically made for horses to control clinical signs associated with PPID. With proper use of Prascend®, Stenborn suggested that PPID horses and ponies can have more energy, a better appearance, decrease laminitis and sole abscess issues, and a more proper shedding ability. Horses and ponies treated for PPID often go back to their old self, but may also have less tolerance to pain.
When treating PPID, it is critical to go about it as a team with a veterinarian. Horse owners need to monitor changes in their horses and let their veterinarian know of any concerns they may have. Horses and ponies and with PPID should have a biannual checkup by a veterinarian. Geriatric horses, as well as horses with PPID, are more likely to suffer from changes in body condition, dental disease, lameness, chronic pain, parasites, and recurrent infections.
“I think the meeting went well. It demonstrated that practices can come together to educate the population for the betterment of the horse. I hope everyone understood that early in the disease the hormone tests may not indicate PPID but if the horse is showing early signs it is better to fret early before it is too late,” said Dr. Wynne DiGrassie D.V.M. with Mountain View Equine Hospital.
With horses living longer than they once did, equine owners and veterinaries are finding different needs must be met. With PPID being an issue primarily in older horses and ponies, the guests at the meeting we eager to learn how to identify the disease and how minimize its’ negative side effects.
by Jennifer Showalter