Maintaining the Health of Older Horses
Within the practice of equine veterinary medicine, equine geriatrics has become an increasingly specialized niche that many veterinarians, including myself, enjoy practicing. Horse owners are keeping old horses around far longer, and they are in better health than ever before. There are many reasons for this. These days, an owner’s loyalty to their old horses outlives their usefulness as a work animal. People have a strong emotional attachment to their old horses. They may have ridden these horses as children, or their children may have learned to ride on them. Regardless, people tend to feel a strong obligation to provide good care to their aging equine friend during their retirement.
Historically, old horses have suffered from a variety of problems as they aged. However, better nutrition, dentistry, and a better understanding of some of the common diseases that afflict them have contributed to an improved quality of life for old horses. In this article, I discuss some of the changes to expect as horses age, and some specific problems that develop in old horses, and how to prevent and treat those problems. I also discuss ways to manage older horses to maximize their quality of life.
THE EQUINE AGING PROCESS
Horses, like people, experience deterioration of all of their body systems as they age. Symptoms that we commonly see include weight loss, difficulty eating, and arthritis. The immune function of old horses is not as good as it is in younger animals. Thus, they are predisposed to disease that might not affect an animal in the prime of life.
Dental disease and inefficient processing of feed is the most common reason for weight loss. Dental problems are common in old horses and are often responsible for difficulty chewing feed and resulting weight loss. Horse’s permanent teeth are a set length. They do not grow but are gradually worn off as they grind against opposing teeth and abrasive feeds. With time, the root of the tooth (known as the reserve crown) moves down through the bone of the jaw and becomes closer and closer to the gum.
So a 6 year old horse might have a 3-4” long molar, deeply embedded in bone. A 22 year old might have a tooth that is only 1-2” long and barely rooted at all. These teeth are predisposed to periodontal disease, pockets of feed and infection around the teeth, which lead to a variety of problems. Often these teeth become loose and may need to be extracted. As horses age, dental over-growths like molar hooks and long teeth and these must be addressed.
The efficiency of gut function decreases with age. Older horses do not have the same ability to digest and absorb feed that younger horses have. This is in large part related to decreasing processing of feed by the teeth. Having well processed, ground feed is critical to the function of the digestive tract. The organisms that break down plant fiber are much more efficient when the particles of feed are small. Large particles are incompletely utilized and much is just passed through in the manure. Poor dental function also predisposes old horses to “choke” or esophageal obstruction. Incompletely chewed feed becomes impacted in the esophagus and often requires veterinary attention. For these reasons, attention to nutrition, management and dental care are critical aspects of caring for old horses.
Also, like humans, horses are at risk for a variety of tumors (cancer). Cancer is much more common in old horses than people realize. Equine melanoma is a unique problem occurring in older gray horses. We expect to see these characteristic hard bumps and masses around the anus, tail, mouth and the back of the jaw in old gray horses, and usually only take note of their size and periodically monitor them. In a small percentage of horses, though, melanoma can actually become a life threatening problem that can be difficult to treat. Many other less common cancer types affect horses. All told, cancer is a significant cause of death in old horses.
Equine Cushing’s Disease, also known as Pituitary Pars Intermedia Dysfunction (PPID), is still an under-diagnosed problem in older horses. In fact, PPID is an extremely common problem in old horses and should always be considered as possibly underlying other problems like laminitis and persistent infections. PPID results from an overgrowth of part of the pituitary gland in the brain. Many horse owners have heard of this disease and associate it with a curly, long coat and abnormal shedding patterns. However, horses can have this disease without showing these classic outward signs. Often horses with normal coats are affected to some degree by PPID.
While all body systems are affected by this disease, the most serious complication is laminitis. Diagnostics and treatment for this syndrome have improved tremendously in recent years. I enjoy diagnosing old horse with this problem because I feel that in many cases, I can dramatically improve their life by making a diagnosis and start an appropriate treatment plan. See Cushing’s Disease/Syndrome – PPID & EMS: What Horse Owners Should Know for more details.
Chronic pain is a major problem for old horses, as it is for old people. Arthritis is the most common source of pain. This usually is chronic and often affects the carpus (knee) and lower limb joints. Proper diagnosis and treatment of this pain also improves the quality of life for horses. Chronic pain can also play a role in weight loss.
In many old horses, there is a combination of many of these factors that contribute to a poor quality of life. When we address these underlying factors, we can really improve their lives. As with most veterinary problems, good preventative care is better than being forced to treat these problems once they occur. Good care through the early and middle years helps prevent many problems and sets an old horse up to have a healthy and comfortable retirement.
MANAGEMENT & CARE
There are now many pelleted “senior feeds” that are balanced and easily digestible nutrition for the older horse. Many of these commercial feeds provide everything an old horse needs. As a horse owner, it is important to be aware of these feeds and ask your veterinarian how incorporating these feeds into your horse’s regimen can help his quality of life. We use Purina’s Senior Feed in our practice and have found it to be a good overall source of nutrition for older horses and other convalescing cases.
Old horses benefit from consistent moderate exercise in the form of pasture turnout or regular light to moderate work. This is, of course, provided that they are not in pain. Vaccination remains an important part of preventative medicine. My recommendation is to vaccinate older horses only for those diseases for which they are really at risk. The incidence of adverse reactions to vaccination is higher in older horses in my experience. A well designed and consistent parasite control program is also essential since older horses are very susceptible to parasites.
Maintaining a high quality of life for old horses is now very possible. Horse owners should understand as much as possible about the equine aging process and diseases affecting old horses. Providing good consistent care to horses through their early and middle years is critical in preventing many common problems of old age. Your equine veterinarian is the person who can help you design a management plan for each stage of your horse’s life.By Douglas O. Thal DVM Dipl. ABVP Board Certified in Equine Practice Thal Equine LLC Last Updated August 2011