This is the second in a three-part podcast series on PPID (pituitary pars intermedia dysfunction, also known as Cushings Disease). You can read about and listen to Part 1 here and Part 3 here.

Click on the player to listen to this episode.

In these three podcast episodes, we cover various aspects of PPID with Hal Schott, DVM, PhD, DACVIM. He is a professor of Large Animal Clinical Sciences at the Michigan State University College of Veterinary Medicine.

In the first episode, we covered what PPID is and clinical signs. We discussed what equids can get PPID, treatments, and what to do if you suspect PPID in one of your senior equids.

Managing a Horse with PPID

There is no cure for PPID. Therefore, every day you must manage the horse appropriately to minimize the consequences of the disease.

Schott said that often these older horses that have PPID are not ridden as much. That means they probably are not thoroughly handled or observed as much as a horse being ridden frequently.

His first suggestion is to take a step back and really look at your horse to see how it is doing once a month or at least once a quarter. Is anything changing? Do you see some long hairs? Is he losing a little topline muscle? Has his attitude changed any?

Schott said in the first episode about PPID clinical signs that he really didn’t talk about how the demeanor changes in a horse with PPID. Sometimes these horses seem to become more docile and lethargic as a clinical sign.

He noted that when you treat these horses with pergolide, one of the things owners see is that these horses often “wake up” a little bit within the first week or two.

“Have a little notebook and make some comments about your guy,” suggested Schott. That includes clinical signs, physical and mental changes, and reactions to treatment.

“You might notice they are a little slower to finish their food. That would suggest that maybe we need to get the dentist out there to take a look at the teeth,” he said.

Management Without Medication

If your horse has been diagnosed with PPID, that doesn’t necessarily mean it needs to be on pergolide (trade name Prascend). Sometimes the clinical signs early on in PPID can be managed without medication. But it might mean some other management has to be put into play.

For example, if your horse is growing a longer, shaggier haircoat that isn’t shedding, you might need to get out your clippers. Schott said body clipping these horses can give them some relief in the springtime when it starts getting warm.

If everything is looking good, the maybe when your veterinarian is out for spring and fall shots, you might ask her/him to look at the horse’s muscle mass. She/he might catch something you have missed.

Get your veterinarian or dental professional to do a good exam at least once a year on these older, PPID-positive horses. It’s better to catch those issues early in the progression.

Schott said horses with PPID might have some chronic founder or laminitis that you aren’t aware. It can happen gradually without a sudden, painful episode. Ask both your veterinarian and farrier if they have any concerns about how the hooves look.

“If you are in an area of the country like I am in Michigan, in the wintertime when the ground freezes up so irregular, sometimes you see horses moving a little ‘funny,’ ” he said. “You might consider hoof radiographs just to see if there are changes. You also might involve your farrier in that discussion to make sure the feet are getting well taken care of.”

Vaccination

Schott recommended making sure your horse is kept up-to-date on its vaccinations. “Just because they’re getting older, that’s not the one top pinch the pennies on,” said Schott. “Make sure they still get that kind of care.”

Preventive medicine such as vaccination and deworming has some debate surrounding what you should do for these PPID horses. One of the most effective ways to protect a horse from disease is through a regular and thorough vaccination program tailored to the individual animal and its situation.  

Vaccination becomes even more essential as our horses age and their immune systems begin to decline (immunosenescence). While senior horses don’t necessarily need more frequent vaccination than normal adult horses, it is important to keep their vaccinations up to date. If a senior horse falls behind on its immunity and gets ill, it often has less capacity to fight off the disease.

(Editor’s note: Read more in Senior Horse Vaccination Procols.)

Deworming

In a previous podcast we visited with parasite expert Martin Nielsen, DVM, PhD (parasitology), DVSc (doctor of veterinary science), DACVM (American specialist in parasitology), and DEVPC (European specialist in veterinary parasitology). He said many senior horses acquire some endocrine metabolic diseases that have been shown to interfere to some degree with the immune response to parasites.

“We also see a tendency to have higher egg counts [in senior horses],” said Nielsen. “Parasite egg counts in those horses does not necessarily mean that they have more parasites. Those parasites are able to crank out more eggs.”

That means the senior horse’s immune system is less able to hold that egg production in check. More eggs means the infection pressure from the number of infective parasites on grass pasture can be higher with this age group.

“So, from the standpoint of parasite control, these horses may be what we refer to as higher shedders,” he said. “We have some specific recommendations to treat them more than we would treat a horse that has a lower egg count because those egg counts tend to be consistent across time.”

If those horses are ‘pumping out’ more parasite eggs, that can increase the parasite numbers in your whole herd.

Dental Care

Schott said that as horse’s teeth begin to wear out, decreased chewing and grinding of hay will lead to atrophy of their masseter (cheek) muscles. So, feeling the masseter muscles in older equids is a fairly easy way to determine whether they can still eat forage.

“That’s when we start to see the real benefits of using some of the senior pelleted complete feeds,” said Schott. “Those senior feeds have certainly extended the life of horses well beyond the lives of their teeth.”

Other Health Issues in PPID Horses

Many older horses have arthritis. “There are medications and supplements that might alleviate some of that arthritic pain,” he noted. Those could include firocoxib or EQUIOXX.

Schott advised to be cautious with supplements. However, making sure your senior gets a good vitamin/mineral supplement—often are called a ration balancer—is important.

Some of these senior horses with PPID also have other infections. They might get a throat, sinus, or skin infection that would require antibiotics from your veterinarian.

Insulin Dysfunction

“If a PPID horse has concurrent insulin dysregulation, the risk of founder is definitely much higher,” said Schott. That is something your veterinarian can test for.

Keeping tabs on a horse’s body condition score and weight is important as it ages. Whether your horse is a little thin or a little overweight, there are management tools and feeds that can help.

“I like to keep it simple when I think about nutrition for horses,” said Schott. “A good-quality forage is the basis of all equine diets as long as they can still chew some hay and/or pasture.

“If they’re overweight and have concurrent insulin dysregulation, the risk for founder is even greater,” he continued. “We’re going to try to restrict their pasture access, especially in the spring and early summer. We need to think of limiting intake of sugars and starches.”

Overweight PPID Horses

If your horse is overweight, then your first step might be to get a weight tape. While they aren’t precise, they can show if your horse is gaining or losing weight.

“Let’s say your horse is 1,150 pounds (522 kg),” said Schott. “And our ideal weight is going to be 1,000 to 1,050 pounds (454 to 476 kg). So we need to lose 100 pounds. Let’s try to get that done over the next three to six months.

“And the way we do that is to actually haul the bathroom scale out to the barn and put your hay in a garbage bag,” he said. “Get on the scale, see your weight, then pick up the bag to see how much it weighs. If you do that three or four times, you get a pretty good idea how much hay the horse needs—about 1.5% of the ideal body weight or about 15 pounds of hay a day.”

He said the horse might not be “completely happy” with his restriction and amount of hay. “So, I think it s really useful to use a slow feeder,” said Schott.

Schott warned donkey owners that they are very metabolically efficient. “The problem with donkeys is they’ll keep eating until there not a flake of anything left. They’re survivors. That might mean slow feeders and muzzles at pasture.”

Exercise and Nutrition for Seniors

“You know, we see everyone taking their dogs for a walk,” said Schott. At the boarding stable or at home, find a little route that you can take your horse for a walk. It’s good for you. It’s good for the horse.

When asked about feed and treats for seniors, Schott agrees these older horses like their food. “I think in terms of the overall amount of food a horse gets every day,” he said. “If it gets to to three flakes of hay twice a day, the extra calories from a handful of a concentrate feed or ration balancer is minimal.

“If you give him a couple of apple slices or carrot slices, that’s just a drop in the bucket for the overall calories that horse has every day,” Schott said. “It’s all relative. I think certainly you can go ahead and give them a treat, but everything in moderation.”

Schott also discussed some research in the UK where ponies were started on a diet program over 12-16 weeks. They got the ponies to lose about 10% of their body mass. “What they found is that the ponies, as they lost weight, their spontaneous activity and moving around increased,” said Schott. “They started noticing the ponies playing with each other even more.

“That shows that even just getting the weight off will help them do their own natural increase in exercise rather than us having to do forced exercise with them,” he said.

Further Reading

Possible New Equine Insulin Dysregulation Treatments. Kimberly S. Brown. MySeniorHorse.com

  • Kimberly S. Brown is an award-winning writer and publisher. She is the Editorial Director for My Senior Horse. Brown spent 10 years at Equine Network, parent company of My Senior Horse. Prior to that she worked for three years in equine nutrition after she retired from nearly 30 years working at The Blood-Horse. Brown spent the last 15 years of her time at that organization creating and developing The Horse and TheHorse.com.
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