6 Common Root Causes of Behavior Problems in Horses

Updated September 9, 2024
very alert horse with ears up

Working with an unpredictable, nervous, excitable horse isn’t fun (for you or your horse), so it’s an important problem to solve. But where do you begin? Start by checking these common root causes behavior problems and you’ll be one step closer to calm.

1. Ill-fitting Tack

Just like you feel your best in clothes that fit, your horse feels his best in tack that fits. If you’re not sure your saddle is the right fit for your horse, consider contacting a saddle fitter for expert advice.

An appropriate and well-fitting bit are also key to a happy ride, so work with your trainer to find and fit the right bit for your horse. Finally, try experimenting with different girth styles. Some horses prefer the fluff of a fleece or sheepskin-lined girth, while others are happier in one that’s non-slip or plain leather.

2. Sugar High

Your horse’s feed is his fuel, so if he’s running too hot, his diet may be too high-octane. Many grains are high in sugars and starches, which can attribute to an excitable attitude. If you’ve got a hot horse, you should aim to feed the minimum amount of grain possible (which may well be no grain at all!).

If your horse can sustain his weight on hay alone, adding a ration balancer or vitamin and mineral supplement is a great way to make sure he has the nutrients he needs without unwanted calories.

3. Stomach Woes

bay horse with ears back

Your grouchy, misbehaving horse may be trying to tell you that his stomach hurts. Over 60% of performance horses have gastric ulcers, and this painful condition can have an adverse effect on your horse’s performance, attitude, body condition, and overall well-being. If you think that ulcers could be the root of your problem, talk with your veterinarian to get a proper diagnosis and design the appropriate treatment plan for your horse.

4. Teeth Trouble

Your horse’s teeth are constantly growing and he wears them down as he chews. However, sometimes they wear unevenly and leave sharp points that not only make it uncomfortable to have a bit in his mouth, but also can make it difficult to chew.

You should have your horse’s teeth checked at least once a year to make sure everything’s in good shape. And if your horse is being fussy or cranky about his mouth, it’s a good idea to have your veterinarian or equine dentist come out to take a look inside.

5. Training Issues

Woman riding while patting her horse on the neck

If you’ve checked out the potential physical causes of your horse’s bad behavior, consider that a training issue could be part of the problem. Working with a qualified trainer will be key to helping you and your horse work through training challenges. And keep an open mind! A trainer from a different discipline or style may have an approach that works better for you and your horse’s unique partnership.

6. Too Little Turnout

Think about how your horse spends his day. How often is he getting out to stretch his legs? Horses were designed to be outside and constantly on the move, not standing in a stall, which is unnatural for them. Providing your horse with as much turnout as possible, ideally with some pasture friends, can help release excess energy and relieve stress.

Supplemental Support

If you’ve worked with your veterinarian and trainer to cross off other possible reasons for your horse’s behavior, adding a calming supplement to their diet may be a smart choice. Some horses benefit from more magnesium than a typical diet provides, and clinical signs of magnesium deficiency include nervousness and muscle tension. Similarly, horses lacking in B vitamins may be anxious, spooky, or unfocused.

Calming supplements can help by providing these nutrients, along with amino acids that support a balanced nervous system. Quiessence provides a great source of magnesium, while SmartCalm® Ultra provides magnesium, vitamin B1, and the amino acid tryptophan to help your horse feel focused and at ease. Herbal calming supplements with ingredients like valerian, vervain, chamomile, and hops can also provide balanced support for nervous horses, but may be restricted by some competitive organizations. SmartTranquility® Pellets provide comprehensive herbal calming support.

For moody mares, herbs like raspberry leaf and chaste berry, found in SmartMare® Harmony, may help support normal hormone levels and a balanced temperament.


SmartPak strongly encourages you to consult your veterinarian regarding specific questions about your horse's health. This information is not intended to diagnose or treat any disease, and is purely educational.