What is Cushing in horses and how do you feed a horse with the so-called PPID?

What is Cushing's in horses, or PPID?

PPID, Pituitary Pars Intermedia Dysfunction, is the legal name for Cushing's disease. In horses with PPID, the function of the hypothalamus and pituitary gland is disturbed. These two are responsible for the production and release of hormones. The hypothalamus produces dopamine, which plays a role in hormone release in the pituitary gland. In fact, when enough hormones have been released by the pituitary gland, dopamine inhibits hormone production.

In horses with PPID, the nerve cells running from the hypothalamus to the pituitary gland branch off, resulting in too little release of dopamine. This keeps the production of hormones from being inhibited.

ACTH is the main hormone that is not inhibited in PPID horses. ACTH stimulates the production of cortisol and plays an important role in normal carbohydrate, fat and protein metabolism. However, because the hormone ACTH is not inhibited, cortisol production is too high in horses with PPID. This causes the cortisol to break down proteins in the muscles, among other things. Both this breakdown, and the way excess cortisol converts carbohydrates, cause a rise in glucose in the blood. This, in turn, causes increased insulin levels, increasing the risk of laminitis in a PPID horse. The cortisol also inhibits inflammatory responses, reducing the immune system.

Proper nutrition is very important for a horse with PPID to stay in good condition and minimize the effects.

Having horse tested for Cushing's by veterinarian

In the fall, the cost of a PPID test at the veterinarian's office is often lower. In addition, tests during this period show higher ACTH peaks because the levels of this hormone naturally rise in the fall. This is also why veterinarians prefer the fall for performing PPID tests.

Feeding horse with Cushing's

Limit sugar and starch

Horses with PPID are prone to laminitis, so it is important to limit the intake of sugar and starch as much as possible. Cereals, which are mainly found in concentrate, contain a lot of starch. It is important that your horse gets enough vitamins, minerals and trace elements. You could choose to feed these as supplements (make sure you choose a supplement without sugary fillers). There are also grain-free balancer pellets, such as our HorseAdds Balance.

Suitable roughage

Coarse-stemmed roughage with low sugar content is preferred. However, coarse-stemmed roughage contains a lot of fiber, some of which is also a lot of hard-to-digest fiber (NDF, ADF and ADL on a roughage analysis). This limits the digestion of protein and fat from the roughage. Since a horse with PPID in particular has a higher requirement for protein in the diet, supplementation in addition to coarse-stemmed roughage of protein and fat may be desirable.

Protein can be supplemented by adding a good protein source to the diet. You can choose soybean meal or soy hulls, soy meal is particularly rich in high-quality protein. Soy hulls are lower in protein (12.5% on average compared to as much as 40-45% in soybean meal), but are much easier to digest, as soy hulls contain an enormous amount of crude fiber.

In doing so, your horse's teeth should still be good enough for coarse-stemmed roughage. Once the horse gets older, this can sometimes cause problems because the teeth can no longer, or not sufficiently, grind the coarse roughage. If they cannot chew the roughage properly, the chances of intestinal blockages or colic increase.

If your horse has trouble eating coarse roughage, then supplementing with a roughage substitute is recommended. Beet pulp, alfalfa, grass meal or (soaked) grass chunks are examples of good roughage substitutes. Lucerne and grass meal usually do contain enough protein to meet the requirement, which in turn makes soy hulls a very good fit here. Soy hulls are an easily digestible and rapidly fermentable source of fiber; they are also called "super fibers." In fact, soy hulls are rich in pectin fibers, these stimulate the growth of positive intestinal bacteria (gut flora) and accelerate their fermentation. Soy hulls aid digestion and support healthy intestinal flora. HorseAdds Fibre consists of 100% soy hulls.

If you want to be sure the forage is appropriate for your PPID horse, have it tested.

What to do when losing weight and/or muscle?

Horses that are emaciated and/or have muscle loss benefit from supplementation of extra energy, high-quality protein and fats. Extra energy in the form of sugars and/or starch is not recommended. Instead, fat, in the form of oil is a suitable source of energy, for example flaxseed oil. To support your horse's muscles, you can feed a high-quality protein supplement. Depending on the type of roughage you feed your horse, you can choose soybean meal or hulls. For severe muscle loss, a supplement with optimal amino acid profile is recommended, as found in our HorseAdds Muscle Build.

Support the horse's resistance

Supporting the immune system

Horses with PPID have a less functioning immune system and are more susceptible to infections. Support is therefore desirable. Provide your horse with adequate antioxidants such as vitamin C, vitamin E and anti-inflammatory omega-3 fatty acids. HorseAdds Immunity can support your horse's resistance through its high lysine content and added vitamin C. Lysine is necessary for antibody formation.

Omega-3 fatty acids and vitamin E

For omega-3 fatty acids, flaxseed oil is the most suitable. It has a very favorable fatty acid profile and is rich in omega-3. Flaxseed oil is also a good source of energy and supports the coat condition. Be sure to add extra vitamin E. The addition of fats increases the need for vitamin E. HorseAdds Natural E provides natural, highly absorbable vitamins at a high dose. With HorseAdds Natural E Oil, you feed natural vitamin E with flaxseed oil.
Vitamin E is important for resistance, muscle metabolism and muscle recovery.

"Horses with PPID are more susceptible to infections. You can support the immune system with omega-3 acids and antioxidants."  

Regulating dopamine levels

In PPID, the functioning of the hypothalamus and pituitary gland is impaired, leading to dopamine deficiency and increased ACTH production. This carries health risks, such as an increased risk of laminitis. Monk's pepper may help regulate dopamine levels, making it useful for horses with PPID.

Feeding horses with Cushing's summarized

In summary, this is the most appropriate feed management for your horse with PPID.

• • Provide adequate, fiber-rich roughage which is low in sugar and starch.
  • Choose a supplemental vitamin, mineral and trace element supplement with no added sugars. Or choose a kibble (balancer) that is very low in sugar and starch. HorseAdds has an appropriate balancer, HorseAdds Balance.
  • Support horses with poor teeth with an appropriate forage replacement, including beet pulp, alfalfa, grass meal/grass chunks.
  • For extra energy, choose a slow-release energy source in the form of fats such as Flaxseed oil.
  • Feed high-quality protein to support muscles and prevent your horse from declining in condition. Soy is a great feed to supplement and choose a supplement, such as HorseAdds Muscle Build, if needed.
  • Support the immune system by providing omega-3 fatty acids and antioxidants. Flaxseed oil is rich in omega-3 fatty acids and has a good fatty acid profile. With HorseAdds Immuniy you can provide additional resistance support. When adding fat, the need for vitamin E increases. With HorseAdds Natural E you can supplement vitamin E. Or choose HorseAdds Natural E oil, where natural vitamin E is added to flaxseed oil. Monk pepper may help regulate dopamine levels
  • Limit grass intake, especially when the sugar content of the grass is high.

If you have any doubts or questions about your feed management, feel free to contact us. A team of nutritionists is ready for you!