Caring for a Thin Horse

The Basics | What to Do: Management | What to Do: Health | Prevention

Horses can suddenly lose weight due to an underlying health problem. The following can help to determine the cause of the weight loss and to minimize potential problems:

  • If your horse suddenly loses weight and/or your horse's body condition worsens, contact your veterinarian.
  • Offer adequate pasture and/or free-choice hay and feeds.
  • Minimize your horse's exposure to sudden environmental changes and slowly acclimate your horse to other changes, such as changes in feed and companions.
  • If high energy feeds such as grain or concentrates are needed to maintain your horse's body condition, you can avoid problems such as gastric ulcers by feeding small, frequent meals rather than one or two large meals of grain daily.

The Basics

Many horses maintain a good body condition if offered a sufficient quality and quantity of pasture and free-choice hay (as needed). Younger horses or horses in work require additional food, such as high energy feeds or concentrates to meet their nutritional needs; older horses often require a senior or complete feed because they lack adequate teeth. If your horse suddenly loses weight, it is important to assess your horse's health and any changes in how your horse is managed.

What to Do: Management

Reevaluate your feeding program to ensure that your horse is being offered enough food daily. Has the quality of pasture or hay changed? If you need to change feed, do it gradually over a few weeks to ensure that your horse adjusts and does not develop a problem, such as colic. When feeding high energy feeds or concentrates, it is best to feed small amounts frequently rather than one or two large meals daily; this can avoid changing the stomach pH too much, which can cause gastric ulcers.

To avoid agitating your horse, slowly introduce him or her to new situations or new herd members in pasture. Horses in a herd have a hierarchy (“pecking order”), so introducing a new horse can change herd dynamics. If a new horse is introduced, it is very important to monitor the herd closely to ensure that the new horse is not being bullied or prevented from eating. If the new horse is being bullied or prevented from eating, separate the horse from the herd. It may also help to feed the horses separately (for example, in stalls) to ensure that each horse receives adequate food and water. It is important to separate certain horses, such as stallions or mares with foals, from other horses on the property and to use separate barns/enclosures and pastures. This will avoid exposing stallions to mares in heat and the problems associated with their interaction, such as lack of interest in eating.

What to Do: Health

Sometimes, despite excellent management and availability of high-quality feed, horses lose weight suddenly. It is important to schedule an appointment to have your veterinarian perform a thorough physical examination on your horse. Your veterinarian may determine that additional diagnostic tests, such as blood tests, are needed to evaluate your horse's kidney and liver function. Horses can develop dental problems, gastric ulcers, or diseases such as pneumonia, or other factors, that can cause weight loss.


It is much more effective to prevent sudden weight loss in your horse than to care for a thin horse that is rapidly losing weight. Providing adequate pasture and free-choice, high-quality hay and/or feed is imperative. If your horse becomes too thin and loses too much muscle mass, (1) your horse will likely become recumbent and unable to stand and (2) your horse's internal organs may undergo irreversible changes, such as heart, kidney, or liver failure.

Developing and implementing a thorough deworming program with your veterinarian, along with regular quality checks (such as fecal egg counts to ensure deworming program efficacy), are vital to maintaining your horse's health. Regular (for example, weekly) manure removal from pastures can help minimize the number of parasites on a farm.

Having your veterinarian perform regular physical examinations on your horse can help to detect problems early, when they are usually more treatable. Asking your veterinarian for tips may be very useful because he or she is accustomed to working with many types of horses and management styles.