"How do we tell when a horse is aged?" asked Nancy Loving, DVM, who owns Loving Equine Clinic in Boulder, Colo., at the recent Healthy Horses Workshop for horse owners (held Dec. 2 in San Antonio, Texas, in conjunction with the 52nd annual American Association of Equine Practitioners Convention). "Most people think a horse is old once he's over 20 years old. But we have to think of physiological age, not just chronological age. For example, some people are old and frail at 70, while some are still playing tennis at 70.
"As the years go by, veterinarians see more and more older horses," she said. "I just lost a horse in my practice that was 42. The record is 62 years old (uncorroborated), and I have seen one at 52; horses in the mid-30s are very common."
Loving said the National Animal Health Monitoring System's 1998 equine study found that 30% of U.S. horses were over age 11, and 8% were over age 20. In a country with more than nine million horses, that's a lot of old horses, many of which have special health care needs. These special needs were the focus of her presentation to the 303 horse owners in attendance.
Maintaining Body Weight/Condition
Some older horses might become too fat, while others lose weight and can't seem to get it back. Loving said an older horse, much like a young growing horse, needs more protein and fat than a middle-aged horse, as well as a source of good-quality fiber. She addressed problems contributing to both weight loss and weight gain in old horses.
Tired of eating "Old horses are slower eaters and they often tire of eating, leaving food to nap," Loving said. "Consider herd competition for these horses; when they get tired of eating, everyone else cleans up all their food. You might have to separate these horses to feed them." It might be inconvenient, but it might be necessary, she said.
Hay type/quality Make sure hay is easily chewed and processed--i.e., it isn't overly mature and stemmy. "These old horses don't have the best dentition to chew poor-quality hay," she said.
Dental issues These might include oral pain, temporomandibular joint (TMJ) disease, periodontal disease, hypersalivation, oral ulcers, sensitivity to cold water, and/or halitosis (bad breath). Any painful dental problem can reduce a horse's willingness to eat, which can mean weight loss for these old horses. Signs suggestive of dental problems include poorly digested feed in feces, cow-pie (loose) manure, and/or quidding (dropping clumps of partly chewed feed on the ground), said Loving. And esophageal choke is a risk when food can't be properly chewed.
As a horse ages, his teeth continually erupt (push out) from the sinuses, unlike human, dog, or cat teeth that grow out and stop at a certain point. Eventually, there's no more tooth left to come down. "All herbivores do this," said Loving. "When their incisors are gone, horses can't do so well on pasture anymore."
As horses get older, their teeth angle out more and the grinding motion changes, said Loving. "Often they get sharp points on their teeth that cause mouth ulcers, which interfere with optimal chewing of food and extraction of nutrients. Use your camera, camera phone, or whatever to take pictures of your horse's body condition to compare to later. You see him every day; you can't see the forest for the trees. You need some objectivity, and this helps.
"Regular dental care can help keep the horse's constantly changing teeth in proper alignment so he can properly chew and get maximum nutrition out of his food to maintain his body weight," she said.
She recommended that an equine veterinary dentist examine and tend to older horses' teeth at least twice annually, and that feed mashes or slurries be fed to older horses with very few or no teeth left.
Concentrates "I'm here to stamp out grain," Loving stated simply. "Horses don't normally consume grains in the wild. All the research shows that there is an increased risk of colic from feeding grain. You might think your horse needs more calories so you offer him grain, but it's processed in the small intestine rather than in the large hindgut, and this creates a potpourri of alterations to digestive health. In any case you can eliminate grain, do so because it can really create problems, such as gastric ulcers, obesity, obesity-associated laminitis, insulin resistance, colic, etc.
"Instead, if he needs extra calories, use beet pulp, rice bran, vegetable oil, alfalfa pellets, or complete feed pellets," she recommended. "Mashes are easier to eat, and it's more palatable if it's easier to eat. Any kind of oil you can find is okay, as horses are very well adapted to using fat as a caloric source."
Old and overweight "The leading cause of obesity is improper nutrition, not endocrine (hormone) disturbance," Loving stated. "I feel that obesity is a form of malnutritional abuse. Overfeeding is often done with the best of intentions, but these horses can founder and experience significant pain.
"Fat becomes an endocrine (hormone-secreting) organ at any age--it increases cortisol (often called stress hormone)," she said. "This can result in insulin resistance and glucose intolerance. (For more information on the metabolic effects of body fat, see "Adipobiology: The Study of Fat".)
"For fat horses, cut their food down to about 70% of their needs--don't crash diet them," she recommended. "Weigh their feed--you can't just eyeball it. Soaking hay in a tub of water is said to remove some of the NSC (nonstructural carbohydrates, or starches) that causes some of the weight problem. Exercise the horse if he has no musculoskeletal problem. Plus horses do just fine with a grazing muzzle to limit feed intake so you can turn them out to exercise on pasture."
Additional Management Strategies
Shelter/blanketing Provide a run-in shed for pastured older horses to get out of the weather. Blanketing might be necessary for some horses, but don't keep them overly warm.
Deworming/vaccinations A horse with internal parasites can look unthrifty and pot-bellied, and he might show uneven shedding or colic. "An older horse should receive at least as aggressive deworming and vaccination strategies as a horse in his prime," Loving commented. "Keep up a good, steady program for all horses in the herd."
Diarrhea, general poor condition, and/or cow-pie feces might suggest parasite infestation, and/or chronic sand ingestion.
Call the vet if he just doesn't seem right Persistent weight loss or a depressed appetite might signal liver or kidney disease, anemia, or cancer. Your veterinarian can help diagnose the cause of poor condition in an older horse.
Air quality Outside air is preferable to maintain respiratory health, said Loving. Feed good-quality hay to keep down dust and avoid moldy hay.
"Keep old horses toned--exercise them, even if it's just pasture turnout," recommended Loving. "That will help keep joints and morale healthy! Stall confinement contributes to colic, and exacerbates arthritis because of lessened joint lubrication, and in addition, soft tissue injuries 'freeze up.' This is not too dissimilar to how you feel after sitting here for four hours," she said with a smile.
Clinical signs of lameness and pain include lying down more often, difficulty rising, pointing a limb (in order to take weight off of it), and possibly chewing on a sore limb or even fences or the barn. "Some horses that are chewing on themselves or the barn stop chewing if you give them some painkiller," Loving said. "Their behavior is a way of communicating to us to do something!"
Osteoarthritis, ringbone, bone spavin, fetlock arthritis, degenerative joint disease, suspensory degeneration, and navicular disease can all cause lameness in any age horse, but these are particularly problematic concerns in older horses, she said.
"A horse should be maintained in a reasonably comfortable state even if he's just standing in a field," Loving said. She discussed several options for managing lameness in older horses:
Nonsteroidal anti-inflammatory drugs (NSAIDs) "These are palliative only; they make horses feel better but don't fix anything," Loving said. "But maybe that's okay. Hazards include kidney failure, gastric ulcers, and ulcerative colitis, which is darn near impossible to fix. I ask my clients, what are we talking about here? One must balance the risk of developing these side effects from NSAIDs vs. a horse's pain and quality of life. If we have tried aggressive medical management, yet he's still hobbling around in pain and/or having difficulty getting up or keeping up with the herd, then it may be practical to try low-dose Bute (phenylbutazone) or Banamine (flunixin meglumine)."
Corticosteroids are helpful when injected directly into joints. However, not all steroids are created equal, she noted. "They provide potent reduction of pain and inflammation and mask damage; some promote cartilage repair, but not all," she said. "Have a conversation with your vet about the best approach in using steroids, and which would be appropriate for your horse's situation."
Hyaluronic acid (HA) given intravenously or into a joint targets synovitis, reduces pain and inflammation, and lubricates joints, she said.
Polysulfated glycosaminoglycan (PSGAG) has been very helpful for some of these geriatric situations, Loving said. "It has an affinity for cartilage, especially if it's damaged," she noted. "It decreases joint inflammation and increases synovial (joint) fluid viscosity (makes it thicker and increases its lubricating ability)." Loving stressed, though, that once there is significant cartilage damage as with arthritis, most of the systemic joint therapies have limited value, but they might be worth a try.
Management options include cold therapy (cold-hosing sore joints), a good warm-up and cool-down for exercise, and long-and-low type riding (with the horse on a long rein moving with a low head carriage) to help keep tissues supple, she said. Stretching can help improve the horse's flexibility.
Acupuncture has been shown, in some cases, to provide relief from musculoskeletal pain, she noted.
Oral joint supplements such as glucosamine have allegedly helped to relieve pain in sore joints, she said.
"You have to provide routine care to the feet because that's just as important as anything else to keep them comfortable," stated Loving. "Some horses can go barefoot all the time, some need boots when riding, and some just don't do well without shoes. Everything is trial and error."
Laminitis is a big risk in older horses, particularly those with hormonal imbalance, she said. Its onset can be subclinical, chronic, and insidious. "Owners need to be very conscious of this," she recommended. "Sinking and rotation (of the coffin bone) are excruciating. It's a very painful way to die, so we want to avoid it at all costs."
Cushing's Disease/Metabolic Syndrome
Cushing's disease or pituitary pars intermedia dysfunction is a fairly common condition in older horses that causes them to be hirsute (overly hairy) and have irregular or delayed shedding, among other clinical signs. "The pituitary gland enlarges and becomes overly active, but is not necessarily tumorous," she explained. "Pituitary activity overstimulates the adrenal glands and the horse's system is flooded with steroids. Puffy eyes (from fat deposits) are a tip that you need to look more deeply into this. Sometimes these horses drink a lot and pee a lot, are potbellied, and/or are susceptible to infections, particularly sinus infections or when they have trouble healing a wound. Having too much corticosteroid in the body causes alterations in glucose and cortisol (so-called "stress hormone") metabolism. It is reported that 70% of horses over 20 years old have apparent or subclinical signs."
Treatment includes dietary management; the medications pergolide, cyproheptadine, or trilostane (which is not currently available in the United States); and/or body clipping the shaggy hair. "You can treat them (medically) for about $1/day," she added. Horses should be treated before developing laminitis--an unfortunately common sequel of Cushing's disease.
Equine metabolic syndrome This leads to obesity and obesity-associated laminitis, but it also has another component--abnormal fat deposition such as a cresty neck or swollen sheath, Loving explained. This syndrome is not peculiar to older horses, she added. Diet modification and exercise are the only treatments at this time.
Hypothyroidism? "I hear so many times that a vet has 'diagnosed' a horse with thyroid problems," said Loving. "There might be thyroid problems secondary to Cushing's disease or metabolic syndrome, but there really isn't primary thyroid disease in horses. If they're on thyroid medications, look at other ways of treating them.
"Fat horses are commonly accused of being hypothyroid, when the predominant ailment that horse suffers from is access to an abundance of calories--a problem created by management and husbandry practices," she said.
Other Health Problems
Cancer/melanoma This is said to occur in 85% of gray horses over 18 years of age, she noted. It can affect the salivary glands, lymph nodes, perineum, penis, and/or eyes, and it can even result in bowel obstruction.
Squamous cell carcinoma. These lesions can appear on the scrotum, perineum, or eyes in horses over 15 years of age. They often start small, she said, so she suggested that the audience go home and look carefully for skin cancers in aged horses.
Pyometra It is not unusual for a mare to develop a uterine infection in her older age. Pus buildup in the uterus (pyometra) can create a space-occupying mass that elicits colic.
Bladder stones As horses age, they might develop deposits of mineral concretions (stones) or sandlike crystals (sabulous urolithiasis) in the bladder; the sandlike debris is very hard to get rid of. Bladder irritation from stones or crystals causes an affected horse to urinate small amounts frequently. You often see the horse straining to urinate, and you might also see urine splatter on the hind legs (mares in back, geldings in front).
Anterior uveitis or moon blindness This causes a painful eye with signs of conjunctivitis (inflammation of the membranes covering the lining of the eyelids), tearing, squinting, photophobia (discomfort from sunlight), and often the eyelids will appear swollen. In a horse with a painful eye, the eyelashes point down rather than out as with a normal horse.
Cataracts These can affect older horses, but they seem to compensate incredibly well if only one eye has reduced vision.
"Old age need not be a burden," said Loving. "Considering all the premium health care we can offer our horses today, there is no reason they shouldn't be living into a ripe old age in the greatest of comfort."
For more information on older horse care, see
Loving's book All Horse Systems Go (available at several retailers, such as Amazon.com: www.amazon.com/All-Horse-Systems-Conditioning-Performance/dp/1570763321).
Get research and health news from the American Association of Equine Practitioners 2006 Convention in The Horse's AAEP 2006 Wrap-Up sponsored by OCD Equine. Files are available as free PDF downloads.
About the Author
Christy West has a BS in Equine Science from the University of Kentucky, and an MS in Agricultural Journalism from the University of Wisconsin-Madison.