If you have a horse that is not gaining or maintaining its weight, here are some reasons and what to do. There are several reasons why a horse may lose weight or not gain weight despite apparent good nutrition.
The most obvious reason for a horse to lose weight is that it is not eating enough. Horses have different nutritional needs throughout their lives. A young horse should be kept healthy, but certainly not overweight, as that brings its own problems. A young horse should be rather lean. You should only be able to feel the ribs, but not see them protrude significantly. Overfeeding at this age can lead to multiple problems.
When a horse enters its working life, simply feeding hay or grass may no longer be sufficient. Most horses that are ridden only occasionally can manage, but a horse that does a lot of work, such as a show horse, a horse that travels long distances, a draft horse used for logging, or a horse engaged in other high-performance activities, may need a supplement of grain or other concentrates. Hay or grass may not provide the energy and nutrients the horse needs. If you compete with your horse, ride demanding trails or haul logs out of the brush every day, your horse may lose weight and need some extra meals to stay in shape. It is not uncommon for broodmares to lose weight when nursing a foal.
Summer weight loss
It is not uncommon for horses to lose weight in the summer months. The heat combined with pesky insects can wear a horse out very quickly. Older horses and those with very sensitive skin are especially susceptible to heat and insect stress. Many thoroughbreds have this problem. Horses that have trouble maintaining their weight in summer should not only be protected from the heat of the day and the bites of mosquitoes and other flies, but should also benefit from supplemental feeding, either with good quality hay in the barn where they can relax and eat without being bothered by mosquitoes or with a concentrate or supplemental feed that encourages weight gain.
Cold weather means your horse needs more energy to keep warm. A warm blanket and cozy protection from wind and moisture will help your horse stay in shape. The best way to keep your horse warm and at a healthy weight is to offer plenty of good quality hay.
Older horses sometimes have trouble staying in good shape. As they age, they may not be able to digest food as well, they may find it harder to keep warm, and pain caused by arthritis or other chronic aches and pains may cause them stress that can lead to weight loss.
Dental problems are the most common reason for weight loss. Horses’ teeth do not grow forever, and over time they can fall out. Even if they haven’t fallen out yet, they can have sharp edges and hooks that make it difficult and painful for the horse to chew its food efficiently. This particular problem does not only affect older horses. Many horses in their prime can also have dental problems that make chewing difficult.
Parasites can appear in horses at any stage of their lives. Regular deworming is important to avoid a heavy load of internal parasites, which not only cause weight loss but also damage internal organs. External parasites can also be a problem. In particular, a heavy lice infestation can cause a horse to lose condition. Foals and older horses can be particularly affected.
In a herd of horses, even in a small herd such as we have on our farms, there are bullies and outsiders. Often, the underdogs are pushed out by the bullet eaters or top grazers. This can lead to weight loss simply because the bullied horse is not getting enough food and is also stressed.
Illness and disease
Many health problems can lead to weight loss. Ulcers are common, especially in performance horses. EPM, HIPP, Cushing’s, EGUS or gastric ulcers, mineral or vitamin deficiencies, and diseases such as cancer or kidney and liver disease can cause appetite and digestive problems that lead to weight loss.
What to do next?
The first step in determining the cause of the weight loss is to determine exactly how much the horse is eating. This may mean separating the horse from other horses for a period of time. Dewormers should be administered and the importance of water in the horse’s diet should not be underestimated. Feeding For Weight Gain offers some advice on feeding your thin horse. If there is no improvement after increasing the amount of feed and deworming the horse, you should see a veterinarian examine the horse’s teeth. If there is still no improvement after dental work, the veterinarian can take blood samples to make sure that no disease is the cause of the weight loss.