Managing overweight horses
Managing a horse’s bodyweight is essential to their over-all health and well-being and can impact performance, reproduction and incident of disease. However, it can be difficult to recognize changes in a horse’s bodyweight or body condition score (BCS) over time. The incidence of equine obesity has increased in recent years and has become a major health issue in the equine industry.
Is my horse overweight?
he first step in managing an over-weight horse is to determine if the horse is over-weight. Owner’s frequently use BCS to help determine if a horse is over-weight. Many agree that a horse with a BCS of 4 to 6 (using the Henneke 1 to 9 scale) is optimal, while horses with a BCS of 7 to 9 are over-weight We recommend all horses be BCS monthly; to learn how to BCS a horse, watch this YouTube video. There are additional methods to determine if a horse is over-weight, including their girth:height ratio, determining a Cresty Neck Score, and utilizing ideal bodyweight equations. For more information on these methods, click here.
Figure 1. Horses were fed from either the stall floor or from a slow-feed hay net.
Impacts of obesity
Horses that are over-weight can have difficulty with thermo-regulation, can be more prone to diseases, and commonly suffer from reproduction issues and poor performance (Figure 1).
- Thermoregulation is a horse’s ability to regulate its body temperature. Obese horses can have difficulty regulating body temperature and are more prone to over-heating.
- Diseases can be impacted by excessive bodyweight. If bodyweight gain is maintained or continues, the horse is predisposed to develop disorders and/or disease conditions. Over-weight horses are more prone to laminitis, Equine Metabolic Syndrome, insulin dysfunction and elevated concentrations of the stress hormone cortisol.
- Reproduction can be hindered when horses are over-weight, making it more difficult to maintain a pregnancy and deliver a healthy foal.
- Performance is impacted by bodyweight. When a horse accumulates excess bodyweight as adipose tissue (fat), performance and functionality are impaired. Baring excess bodyweight impact hoof health by negatively affecting the integrity of the hoof wall, heel buttress and bars of the foot. Obesity is a risk factor in the development of osteoarthritis and negatively impacts joint health. Finally, excessive bodyweight increases musculoskeletal pain, resulting in decreased functionality.
Diet and exercise: Keys to reducing bodyweight
Restricting a horse’s caloric intake and a slow but steady increase in exercise are keys to reducing bodyweight. There are negative consequences to having a horse that is over-weight, but there are also negative health consequences if an obese horse loses bodyweight too quickly. When managing over-weight horses, it is important that the horse lose bodyweight slowly and steadily over time.
Over-weight horses should have their diet limited to 1.5% of their bodyweight each day. Horses at an ideal bodyweight usually consume about 2% of their bodyweight in feed (includes hay, grain and supplements) each day. For example, a 1,200 pound horse should receive 18 pounds of feed (hay and/or grain) each day. It is best to provide a majority of feed in the form of a mature grass hay; this hay type usually contains that least amount of calories. It is important to weigh out hay flakes to determine the correct amount since different bales and hay types will result in different weights. Using a slow-feed hay net can help extend the length of time it takes for a horse to consume a hay meal. For more information on slow-feed hay nets, click here.
Although over-weight horses need to be on restricted diets, it is important their diet be balanced. An effective way to accomplish this is to feed a ration balancer. Ration balancers are commercially prepared horse feeds that are designed to provide the trace minerals and vitamins a horse requires. The minerals and vitamins are concentrated so that only a small amount needs to be fed, typically 1 to 2 pounds a day for a 1,000 pound horse, depending on the product. For more information on ration balancer, click here.
Over-weight horses rarely require additional grain or concentrates and should have pasture access restricted. Using a grazing muzzle restricts forage intake by an average of 30%. As long as the grazing muzzle fits well and the horse can easily access water, grazing muzzle should remain on over-weight horses if pasture access is granted. Owner can also limit the amount of time a horse spends grazing by housing them in a drylot for a portion of the day. Limited grazing, plus restricted hay access while housed in a drylot should result in bodyweight loss. Restricting grazing while offering free access to hay will rarely result in bodyweight loss.
Exercise not only burns calories and decreases the amount body fat that is accumulating, it also enhances the health and capabilities of muscle and bone. When a horse is over-weight, it is very important to plan a slow and steady increase in activity coupled with a decrease in calories until the horse reaches it bodyweight or BCS goals. A common exercise plan for an over-weight horse includes starting with a 30 minute combination of walking and slow trotting two or three times per week. As the horse loses bodyweight and gains fitness, the intensity, duration and frequency of exercise can increase. Exercise, combined with a reduction in calories, can have a powerful impact on bodyweight loss that can’t always be achieved with exercise alone.