In our years dealing with equines collectively, we have encountered many cases of equine obesity. Sadly, the obese horse faces challenges that even stark emaciation cases do not, and that is a life long battle to overcome their condition. Obesity is painful and can turn into a chronic health condition that requires intense management. The thin horse can recover at a rapid rate and go onto have no lasting issues at all.
So when we talk about equine weight, while our hope is ALL horses can live at healthy body scores, the truth is, the average future of the neglected thin horse is less painful and has a better prognosis than that of the obese horse.
Certain equines are more prone to obesity, such as Quarter Horses, Drafts and Ponies; however, there is no real limitation to what horses can easily become obese.
The lush pastures of today, the rich concentrated feeds, limited exercise and the poor understanding of a horse’s nutritional needs by many horse owners have added up to a recipe for disaster for our equine buddies.
It is up to an owner to realize they are dealing with a horse that is too easy a keeper early on because an easy keeper, if mismanaged, can become a horse with Equine Metabolic Syndrome. EMS is not especially well understood, but it seems that generally, this condition is man created. While most horses will not develop this condition, once a horse has EMS, you are often going to be dealing with a life long battle to keep the horse sound and healthy. The fact your horse does not end up with a chronic metabolic disorder does not mean you have not risks with obesity in your horse.
Obese horses have issues in hot weather with sweating and overheating. Saddle fit is difficult. Fatty tumors are more common in overweight horses, and fat mares tend to stay in heat more often (through winter) than healthy horses. Organs can be compromised, and of course, the greatest risk, are to your horse’s feet. Lamanitis (or the chronic form, called Founder most often) is commonly associated with obese horses:
"Laminitis is the inflammation of a network of blood vessels, known as the laminae, within the hoof—a very painful and often fatal condition. The inflammation reduces the laminae’s ability to integrate and hold the hoof wall and the coffin bone together. Thus, with severe laminitis it is possible for the coffin bone to rotate downward and protrude through the sole of the foot."
If you have a horse that tends to carry notably higher body condition than his herdmates, do some things early on before you are dealing with a lasting health condition like:
- Exercise this horse more
- Use a grazing muzzle
- Stop feeding concentrated feed in favor of average quality hay
- Consider a dry lot
- Make changes gradually to prevent stress (there is a stress condition to obesity)
- Do not resort to 24/7 stall time
"Prevention of EMS should focus on maintaining normal weight in horses, particularly in high-risk breeds. Because these horses may be more efficient users of ingested calories than others, it is imperative to feed appropriately to maintain an ideal condition score and not to use arbitrary feeding guidelines. Particular care should be exercised when turning horses on pasture during times of high-soluble carbohydrate content, eg, spring and autumn."
Keep in mind, BECAUSE metabolic issues OFTEN arise from initial misfeeding of horses (man created), you need to know how to feed the easy keeper before acquiring such a horse to best prevent the horse found foundering or developing EMS.
For IR Horse Diet, read here:
http://animalscience.uconn.edu/extension/publications/insulinresistance.htm
For additional reading, try:
http://gettyequinenutrition.biz/Library/Obesity.therealcause.therealfix.htm
https://www.bluecross.org.uk/pet-advice/horse-obesity-prevention-and-management
http://www.thehorse.com/articles/33375/health-concerns-related-to-equine-obesity
https://www.thehorse.com/articles/38958/feeding-horses-with-endocrine-disorders