Underweight Horses

We all know the dangers of overweight horses, but underweight horses are also at risk of various health problems, and knowing what to feed to help them build condition can be tricky.

Before you start changing their feed, it’s best to check that there are no major health problems that are causing your horse to lose weight. Horses with poor teeth will struggle to eat and can lose weight very quickly, as can those with ulcers. If your horse has been losing weight without you reducing their feed or upping their work, it’s wise to have them checked over by a vet. They will be able to advise you of any major changes that need to be made to their diet.


Horses spend around 16 hours each day grazing so, if possible, feed them little and often. Small meals are far easier for the horse to digest, and frequent feeding times will help prevent horses in a stable from becoming bored.

Feeding one large meal a day and limiting forage can put an underweight horse at risk of ulcers. Instead, have forage available for them to graze at all times, supplementing this with smaller meals throughout the day.


While forage is essential when it comes to feeding an underweight horse, it’s not particularly calorie dense. Adding fat to their food allows you increase their calories without filling their system with high energy starch or sugar. The best way is to add either vegetable oil or corn oil, starting with just a little if they are not used to it, and adding more each day.


Underweight horses should be eating hard feed that’s high in fibre. This is a slow release energy source and will help your horse to consume more calories without becoming fizzy or hyperactive. High fibre hard feeds are readily available and, combined with an easily digestible high fibre source like sugar beet, can go a long way towards helping your horse gain weight

What to Avoid

It’s often the fizzy and hyperactive horses that struggle to put weight on, and while sugar and starch may seem like a quick fix when it comes to quickly upping their calories, it may only exacerbate the problem.

Reducing reactivity is key, and this will require lowering sugar and starch while adding fibre and fat. Too much sugar without enough work will only cause your horse to get more stressed which will be counterproductive. Plus, if your horse is in ridden work, you may find yourself with more a little more fizzy than you bargained for!

When it comes to keeping your horse in perfect condition, there are no quick fixes. Instead, it’s about finding the magic formula that works for your horse – slightly adjusting it when necessary. Horses can naturally lose weight in winter and this is usually nothing to worry about, but if they struggle to put on condition even when the spring grass comes through, you will need to be a little more proactive.

Remember that the bulk of the horse’s diet should be forage, and any changes should be made slowly in small steps. Providing your horse is otherwise healthy, a few minor tweaks and a little patience are usually all that’s needed to help your horse gain weight.