If your horse has Cushing's disease, this guide starts where it should: work with your veterinarian. PPID is a medical condition that needs veterinary diagnosis and lifelong management. Everything here is meant to support your vet's plan, not replace it.
With that clear, let's talk about why horses with Cushing's often lose weight and muscle, and how good nutrition and steady monitoring can help alongside treatment.
What PPID is, in plain terms
Cushing's disease in horses is properly called PPID, which stands for pituitary pars intermedia dysfunction. It is a slow, common disease of older horses. The UC Davis Center for Equine Health explains that part of the brain loses its normal control over the pituitary gland, so the gland overproduces certain hormones. Research suggests PPID affects roughly a fifth to a quarter of horses over the age of 15.
There is no cure for PPID, but it is manageable. The only licensed medicine is pergolide, and your vet will guide dosing and monitoring. Diet, exercise, and good general care round out the plan.
Why PPID horses lose weight and muscle
The hormone changes in PPID affect the whole body. Common signs include muscle loss along the topline, a pot-bellied look, a long curly coat that does not shed on time, more drinking and urinating, and a weaker immune system. The University of Illinois College of Veterinary Medicine lists muscle wasting and weight loss among the classic signs.
Two things drive the weight and muscle loss. First, the hormone changes break down muscle. Second, older PPID horses often have worse teeth and absorb feed less well. Put together, the horse can lose topline even on a reasonable diet.
How nutrition supports the plan
Diet does not treat PPID, but it helps the horse hold condition while the medicine does its job.
- Quality, digestible calories. Older horses often do better on softer, easier-to-chew, highly digestible feeds.
- Good protein and amino acids. These support what muscle the horse can keep and rebuild, especially with gentle exercise.
- Watch the sugar. Many PPID horses also have insulin problems and laminitis risk, so your vet may advise a lower-sugar diet and limited rich pasture.
- Regular dental care. Better chewing means better use of feed.
Always make changes with your vet, since the right diet depends on whether your horse also has insulin or laminitis issues.
Where monitoring fits
PPID management is all about tracking changes over time. Your vet will monitor hormone levels and overall health. Alongside that, you can keep your own records: body condition scores, photos, weight tape numbers, shedding, and energy.
A hair mineral analysis can be one part of that monitoring picture. It screens trace minerals and heavy metals and gives a baseline you can revisit over time. It is a screening and monitoring tool only. It does not diagnose or treat PPID, and no supplement treats PPID. Use it to support the conversation with your vet, not to replace any part of the medical plan.
Want a nutrition baseline to share with your vet? Order a hair mineral analysis test kit as a complement to veterinary care.
When to call your vet
Contact your veterinarian promptly if your PPID horse shows:
- Faster weight or muscle loss than usual
- Any sign of laminitis, like foot soreness or a reluctance to move
- Repeat infections, slow healing, or a sudden drop in energy
- Changes in drinking, urinating, or appetite
These deserve a prompt veterinary check, since PPID horses can be more fragile.
A simple daily care checklist
Good daily care helps a PPID horse hold weight. Keep it simple and steady.
- Give the medicine as directed. Your vet will set the dose.
- Feed quality, easy-to-chew food. Older horses chew less well.
- Keep clean water close. Good water helps appetite.
- Watch the feet. Foot soreness can be an early sign of trouble.
- Keep a record. Note weight, coat, and energy each week.
Diet do's and don'ts
The right diet depends on your horse. Many PPID horses also have a sugar problem. So the rules can differ. Work with your vet. Here is a simple guide.
- Do feed soft, easy-to-chew forage if teeth are worn.
- Do add quality protein to help keep muscle.
- Do not feed lots of sugar or rich spring grass if your horse has a sugar problem.
- Do not make big feed changes fast. Go slow.
Track changes over time
PPID care is a long game. You manage it for life. So tracking matters.
Take photos from the same spot each month. Use a weight tape. Note shedding and energy. Share these notes with your vet. Small changes are easy to miss day to day. A record helps you catch them early.
Questions to ask your vet
Come to each visit ready. A few simple questions go a long way:
- Is my horse's dose still right?
- Does my horse also have a sugar or insulin problem?
- What body condition score should I aim for?
- Which feeds are safe for my horse?
- What signs mean I should call you right away?
Write the answers down. A clear plan is easier to follow day to day.
Common questions
Why is my Cushing's horse losing weight?
The hormone changes of PPID break down muscle, and older horses often chew and absorb less well. Together that can cause weight and muscle loss even on a fair diet. Your vet should guide treatment and diet.
Can diet or supplements treat Cushing's?
No. PPID is managed with veterinary care and the medicine pergolide. Diet and monitoring support the plan but do not treat or cure the disease.
Is mineral testing useful for a PPID horse?
It can be one monitoring tool to screen minerals and heavy metals and set a baseline. It is not a diagnosis and does not replace your vet's testing.
PPID is a vet-led, lifelong management story, and good nutrition plays a supporting role. Keep your vet at the center, support condition with the right diet, and monitor over time. Order a hair mineral analysis test kit as a complement, and see the complete guide to weight loss in horses for related causes.
Sources:
UC Davis Center for Equine Health. Pituitary Pars Intermedia Dysfunction (PPID): https://ceh.vetmed.ucdavis.edu/health-topics/pituitary-pars-intermedia-dysfunction-ppid
University of Illinois College of Veterinary Medicine. Pituitary Pars Intermedia Dysfunction (PPID) in Horses: https://vetmed.illinois.edu/pet-health-columns/ppid-horses/
Merck Veterinary Manual. Clinical Signs of Pituitary Pars Intermedia Dysfunction: https://www.merckvetmanual.com/multimedia/table/clinical-signs-of-pituitary-pars-intermedia-dysfunction
Kirkwood NC, et al. Pituitary Pars Intermedia Dysfunction (PPID) in Horses. Vet Sci. 2022 (PMC9611634): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9611634/
Merck Veterinary Manual. Equine Metabolic Syndrome: https://www.merckvetmanual.com/metabolic-disorders/equine-metabolic-syndrome/equine-metabolic-syndrome