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Horses with Metabolic Issues | Groundmaster

For Horses with Metabolic Issues, Springtime Is Hard

The days are getting longer, the weather is warming, flowers blooming, the grass is green and growing… It couldn’t be a more perfect time of year! Unless you have horses with metabolic issues. 

Photo by Roger Starnes Sr on Unsplash  

Metabolic issues in horses include equine metabolic syndrome (EMS), insulin dysregulation (ID), or pituitary pars intermedia dysfunction (PPID, formerly called equine Cushing’s disease). Horses who have or are prone to one of these issues and horses who have not been on pasture require careful management and transition when lush spring pastures appear.  

Does My Horse Have Metabolic Issues?

This is a conversation best had with your veterinarian, as blood tests will be the best diagnostic tool

Risk Factors for Horses with Metabolic Issues

Risk factors vary but may include weight (obesity), age (PPID is more prominent in horses over 20 years old, insulin resistance can start at any age), and a diet high in starch and sugar. Some breeds seem more predisposed to metabolic issues, including ponies, donkeys, Paso Finos, Arabians, and Morgans.

Symptoms of Metabolic Issues

Symptoms for each condition vary, but here are some key signs that you should share with your veterinarian: 

  • Chronic or recurring laminitis, in the absence of other cause 
  • Your horse may be overweight, average weight, or as is sometimes the case with PPID horses, very skinny 
  • Abnormal fat pockets along the crest of the neck, rump and tail head, and abdominal area 
  • Symptoms of Insulin Resistance include the above with excessive thirst, drinking, and urination 
  • Symptoms of PPID/Equine Cushing’s include the above plus increased coat length, delayed shedding in spring, excessive sweating, and lethargy 

Preventing Metabolic Issues

Preventing metabolic issues before they begin is the best approach. Starting from as early an age as possible,

Maintain a Healthy Weight and Body Condition

Feed a diet that is appropriate for your horse’s life stage and exercise level. Just like your doctor tells you – too many calories with too little exercise isn’t generally a good combination. Your veterinarian, trainer, and coach make an excellent team to help you know how much of each your horse might need depending on what you’re doing with him. Ideally, you want to keep your horse’s body condition score between 4 and 6.

Young, growing horses out with a herd on pasture may need calories. If your horse is in heavy training or ridden several times per week (such as lesson horses), he may need more protein and fat

Feed and Hay Low in Sugar

Look for balanced feeds and good quality hay with low levels of starch and sugars (soluble carbohydrates).

Be sure to have your hay tested by a reputable lab. Growing season, soil health, etc., determine the hay’s sugar and starch content. It’s not unusual to have hay test significantly different from cutting to cutting and year to year. Feeding hay that tests the combined sugar and starch level under 10% is ideal. According to David Ramey, DVM, soaking hay in water for 15 to 60 minutes can help remove nonstructural carbohydrates.

If your horse has been off pasture over the winter, transition them back to the pasture slowly in the spring. When grasses are growing rapidly, they tend to have less fiber and contain more sugar.


Just like us, horses need ample exercise to stay healthy. If you’re unsure how much exercise your horse needs, again, look to your team that includes your veterinarian, trainer, or coach.

Remember, exercise doesn’t always mean sweating! There’s a time for hard, focused work in the arena. But groundwork and “play” also counts as exercise! Have you tried doing liberty with your horse? Trick training? How about a giant horse ball?

Don’t forget trail and pasture riding. Just getting on and riding for fun is good for both of you! There are lots of fun ways to enjoy your time with and exercise your horse.

Treating Metabolic Conditions

Nowadays, there are many treatment options available for horses with metabolic conditions, both pharmaceutical and natural.

Natural Treatment

  1. Lifestyle changes, including increased exercise and a reduced-calorie diet, are most often recommended 
  1. Be aware of the carbohydrate content in hay being fed. Have your hay tested.  In an article for theHorse.com, equine researcher Ray J. Geor, BVSc, Ph.D., Dipl. ACVIM, pro-vice-chancellor of the Massey University College of Sciences, in Palmerston North, New Zealand, recommends that the nonstructural carbohydrate content of the hay (starch plus ethanol soluble carbohydrates) be under 10%   
  1. Limit pasture grazing, or use a grazing muzzle 
  1. DO NOT feed grains, carrots, apples, or sweet feeds 
  1. Avoid supplements that are soybean meal-based or high in sugar content 
  1. A recent year-long, veterinarian-led trial in Canada indicated that supplementing IR horses with a combination of cinnamon and cranberries significantly reduced glucose and insulin levels 

Medical Treatment

The most commonly prescribed medications for equine metabolic issues include:  

  • Prascend (pergolide mesylate) for PPID (Equine Cushing’s Disease) 
  • Levothyroxine sodium 
  • Metformin 


Diet, exercise, and veterinary support are essential to preventing, identifying, treating, and managing metabolic conditions in horses. Whereas prevention is the best treatment, you don’t always get the opportunity. Diagnosis is not a death sentence. Some symptoms can be reduced. Most are definitely manageable!

Do you have a horse with metabolic issues? What have you done that has been effective in helping him lead a more comfortable life? We’d love to hear from you!



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