PPID or Cushing’s Disease in Horses

What is PPID?

PPID, which was historically known as Cushing’s, is a degenerative endocrine disorder that disrupts the control of hormones produced in the pituitary gland, and commonly affects older horses and ponies.

What are the symptoms of PPID/Cushing’s Disease  in horses?

  • Longer, thicker coat that fails to shed in the spring
  • A pot-bellied appearance
  • Excessive urination and drinking
  • Lethargy
  • Loss of muscle tone
  • An increased susceptibility to laminitis

If you are worried that your horse or pony is showing signs of PPID/Cushing’s Disease then you should consult your vet who may carry out a blood a test. Veterinary medication prescribed by your vet can help to manage the symptoms and help regulate your horse’s hormone levels.

What is the cause of PPID/Cushing’s Disease in horses?

PPID is caused by neurons in the hypothalamus gradually degenerating over time. These neurons are responsible for releasing dopamine to inhibit the production and release of hormones from the pars intermedia, which is one of the three lobes of the pituitary gland. In the absence of a signal to stop, the pars intermedia continues to produce hormones, leading to high levels circulating in the body. This results in some of the common symptoms of PPID/Cushing’s Disease, including a longer, curly coat that fails to shed, a dipped-back and pot-bellied appearance, excessive drinking and urination and an increased susceptibility to laminitis.

How to manage PPID

The underlying endocrine problems of PPID/Cushing’s Disease can increase the risk of laminitis in horses and ponies. Those that have EMS, as well as PPID are at an even greater risk of laminitis. The trigger that ultimately results in the clinical signs of laminitis is often diet-related and is usually due to excessive consumption of sugar and starch. Therefore, when looking for suitable feeds for horses and ponies diagnosed with PPID/Cushing’s Disease the advice is to choose products that are low in sugar and starch. The recommendation is that the non-structural carbohydrates (NSC), which are a combination of water-soluble carbohydrates (WSC, or ‘sugar’) and starch is less than 10-12% when combined.

Top Tips From Our Equine Nutritionists

Here are four top tips that our nutrition team advise for horses and ponies with PPID/Cushing’s Disease

  1. Monitor your horse’s weight

Get in the habit of checking your horse’s weight by both weigh taping and body condition scoring on a regular basis. Aim to keep your horse or pony at a healthy weight. Click here to learn how to monitor your horse’s bodyweight.

  1. Ensure your horse’s diet is balanced

A balanced diet is very important as horses with PPID/Cushing’s Disease may have a compromised immunity and poor skin condition. If you are feeding less than the recommended amount of a fortified feed or if you’re feeding your horse a fibre only diet, it’s necessary to add a broad-spectrum vitamin and mineral supplement or balancer to ensure your horse’s diet is balanced.

  1. Check your horse’s teeth

Other age associated issues, such as dental issues may also need to be considered when selecting an appropriate horse feed. As PPID/Cushing’s Disease tends to affect older horses, poor teeth may be an additional problem to overcome. High-fibre feeds that can be soaked, such as Dengie Alfa-Beet, may be easier to chew and can be used as partial hay replacers.

  1. Entice their appetite with different feeds and flavours

Horses with PPID can be fussy. Offering different types of high-fibre feeds may tempt them to eat. If your horse doesn’t eat much hay in the stable, try offering a bucket of chopped fibre feed alongside to see if you can encourage your horse to eat more fibre. Secondly, try feeds with different flavours or herbs to temp them.

Which Dengie Feeds are suitable to feed a horse with PPID/Cushing’s Disease?

Horses and ponies diagnosed with PPID/Cushing’s Disease should be fed a low sugar and starch diet. As alfalfa is naturally low in both sugar and starch, there are a number of feeds in our range that are suitable. Your horse’s diet should be balanced and provide a level of energy appropriate to your horse’s condition and workload – not all horses with PPID/Cushing’s Disease are overweight!

Low calorie horse feeds for overweight horses or those in light or no work:

High energy and conditioning horse feeds for underweight horses or those in work:

Horse Feeds for those that maintain a healthy weight:


PPID Case Study

Chewy is typical of many horses in that he was diagnosed with PPID when he was 22-years-old following repeated bouts of laminitis. Tests established Chewy had both PPID and Equine Metabolic Syndrome.

After speaking to our nutrition team, Chewy’s owner, Rebecca changed his diet to Hi-Fi Lite with a vitamin and mineral supplement. His progress and weight were monitored – at his heaviest he weighed 468kg.

Recommended Diet

Bucket Feed – 1kg of Hi-Fi Lite, split over three feeds a day

Forage – 5kg of hay, divided between 1kg post-lunch and 4kg at night

Grazing – Five hours of turnout from 7:30am to 12:30pm, wearing a grazing muzzle during the spring and/or autumn abundance of grass.

Thanks to a change of diet and our nutrition team’s advice Chewy lost 70kg and at his lightest weighed 400kg. Since losing the excess weight Chewy has been free from laminitis. His weight fluctuates a little due to spring and autumnal grass flushes, but he’s healthy and in great shape.

Click here to read Chewy’s story in full.