Old age treats some horses better than others. Many continue to lead happy, healthy lives well into their 30s--a little slower, maybe, with some loss of muscle tone or a bit of a swayback, but otherwise in good flesh and good spirits until they're well past the Age of Majority. But we've all seen geriatric horses who suffer a debilitating decline. The weight seems to drop off them until they're virtually skeletal, with protruding spinal processes and hip bones, sometimes even when they're well-fed.
What causes this transformation from horse to bone-rack? Often, dental problems are to blame. Geriatric horses frequently suffer from profound dental difficulties, which are compounded if they haven't had the benefit of regular tooth care throughout their lives.
Unlike human choppers, a horse's teeth continue to erupt from his jaws throughout his life. His natural diet of gritty, fibrous plants is supposed to keep the surfaces of the teeth ground down to a reasonable length (in much the same way a rodent keeps his teeth in trim by gnawing wood). But sometimes the softer grasses, hay, and grain of a domestic diet fail to provide enough "sandpaper" to
keep the teeth properly worn. Then, sharp edges, hooks, and other problems emerge, seriously interfering with the horse's circular chewing motions and making it impossible for him to correctly process his feed.
Then, too, sometimes old horses just outlive their teeth. Modern veterinary care has extended the natural lifespan of horses past what we'd expect to see in the wild. The teeth generally stop erupting around the age of 20, because there's literally no more tooth left in the jaw. From then on, their surfaces continue to grind down, until some horses are left with only nubbins of tooth protruding from the gum, or sometimes a smooth, flat sliver of crown that resembles a Chicklet and has no appreciable chewing ability. With only the tips of the roots still holding such teeth in the jaw, it's common for the molars, in particular, to become loose, especially when the back of the mouth suffers from periodontal disease (opportunistic infections that take advantage of gaps between the tooth and gum and cause irritated tissues and even nasty abscesses).
When a horse loses a tooth, the opposing tooth in the opposite "arcade" (row of teeth in the jaw; i.e., top vs. bottom) is left with nothing to grind against, and might start to grow out of control. This can create a chain reaction of problems--at the least, an accumulation of sharp points on the molars, and at the worst, "step (or ramp) mouth" or "wave mouth." In a wave mouth, the surfaces of the teeth develop a ripple effect, which affects the horse's ability to grind food, because the upper and lower arcades don't meet correctly. A step mouth, which is more severe, results when a missing tooth causes the arcades to wear on diagonal lines, like the steps on a staircase. Left unaltered, situations like that can severely compromise a horse's ability to chew, and sometimes leave him with a mouth that's ulcerated and raw.
Although molars are the teeth most likely to suffer problems in geriatrics, older horses also can be challenged by damaged incisors, which can make grazing or eating long-stemmed hay very difficult. The equine canines (sometimes called tushes) also can crack, split, or abscess, causing mouth pain and sometimes infection.
When a horse can't chew properly, he can't extract the nutrition he needs from his diet, no matter how balanced or digestible it is. Combine the likelihood of dental difficulties in older horses with his decreased ability to absorb certain nutrients in the gut, and it's easy to see why some geriatrics begin to look like victims of famine, even when they're provided with lots of feed.
Fortunately, good dental care provided by your veterinarian can address many of the tooth problems of older horses and often can restore them to good health and good flesh. The trick is to find a veterinarian who truly is dedicated to thorough dental care, and has an understanding of the particular problems of geriatrics. One of the biggest concerns with geriatric teeth is that the longer abnormalities go untreated, the worse they become. Even horses which have had their teeth floated on a yearly basis sometimes have never really had their problems addressed correctly.
Fred Faragalla, DVM, has specialized in equine dentistry for the past nine years, and has a particular interest in geriatric horses. From his base in North Carolina, he travels to treat a wide variety of clients' horses, and he notes that a properly cared for mouth can have far-reaching effects.
"I got involved with (dentistry) as a means of colic prevention, and I now treat very few colics, because I help the horse most through his mouth," he says.
In order to effectively examine the mouth of a geriatric horse--or any horse, for that matter--you need to employ a speculum, says Faragalla. A speculum is a device that straps over the poll and gently holds the horse's jaws open. It might look like a medieval torture instrument, but its purpose is to allow access even to the back molars, which otherwise may go unexplored. Since most horses find the speculum a little obtrusive, a mild sedative generally is called for (the sedative also simplifies the process of floating the teeth).
"You've got to examine the mouth, both with lights and mirrors, and with your hands," Faragalla says. "If you haven't touched the back part of the third molar, you haven't done a thorough dental exam." Statistically, the third and fourth molars (there are six in all, in each arcade of a normal mouth) are the most vulnerable to damage and to periodontal disease, according to a survey of equine mouths conducted at the University of Illinois.
Loose teeth probably are the biggest problem Faragalla sees in geriatric horses. "In old guys I tend to see terrible shaped teeth, worn teeth, extremely sharp teeth... but most of all, loose teeth, or teeth that are worn to little nubs with loose roots," he confirms. "If they're loose, they should come out, because chances are there's an infection, and there's probably no root structure to speak of left anyway.
"When there's a pocket of infection around the root, and you pull the tooth out, there's this awful odor," Faragalla says. "The horse is better off without it." He notes that when working on geriatrics, there's always a hazard of loosening the teeth during floating, but for the most part teeth that don't hold firm are less than healthy.
Alan Young, DVM, who acts as the team veterinarian for the Canadian three-day event squad, notes that "an awful lot of (geriatric) teeth are loose because they haven't been maintained and are being driven loose by abnormal teeth in the opposite arcade. Often all you have to do is grind off the steps or ramps, and the teeth will stabilize."
Young recently invested in a new system of dentistry tools powered by a portable air compressor, and he credits the equipment with significantly changing his view of equine dentistry. "A lot of vets don't enjoy doing teeth," he says. "I certainly never enjoyed it till I got this. I realized how necessary it was, especially for performance horses, because so much of what a rider is telling them comes right through the lower jaw, through the temporomandibular joint. But it wasn't till I got this (system) that I could really say I enjoy doing teeth. I find now I can effect greater changes, without ripping the tissues on the inside of the mouth to shreds, and I can guide the floats with my finger, so it can be very specific. With manual floats, or the big electric floats, you have both hands outside the mouth; an electric float would take your finger off if you put it in the wrong place."
The air compressor tools, adapted from tools used for human dentistry, are particularly useful for geriatrics because the amount of pressure used is adjustable. "If there's any possibility of periodontal disease or loose teeth, you can be very gentle by lowering the air pressure and working away more quietly," Young explains. "And there are different sizes and shapes of floats for different jobs--for the upper arcade, for the lower, for reaching over the tongue to address the hooks that form on the first premolars--which is pretty nice because you can actually get where you need to."
Faragalla notes that while it is often possible to dramatically change severe dental problems, such as "shear mouth" (a condition in which the upper molars overshoot the lower ones, creating dramatically sharp points), discretion often is the better part of valor. "In my opinion, problems that the horse has been living with and compensating for over a number of years are best left alone," he says. "Making major corrections in a geriatric horse sometimes causes a whole new set of problems. The key thing is to gently take the sharp edges off and keep them comfortable."
He noted, however, that his approach will vary depending on the degree of difficulty the horse is having with his feed and with how abnormal the interior tissues are. "If it's an old guy not having any problems, not losing weight or choking or colicking, I stay conservative when I float," Faragalla says. "But if I see he's having a lot of problems--ulcerations and sores inside the mouth, a foul odor, big 'quids' (large, half-chewed wads) of hay falling out when he eats, or excessively long teeth that are limiting the amount of chewing he can do--I'll be more aggressive in correcting it."
Young finds that many cases of wave or step mouth that he observes stem not from missing or loose teeth, but simply from a horse's habit of chewing on one side of his mouth, or from variations in the amount of wear the tooth enamel can take. "When you end up with one tooth that's protruding, maybe that tooth is just a little bit harder, or the surrounding ones are just a bit softer," he says. Whether these variations result from genetics, environment, diet, or a combination of factors, the best approach is to keep on top of the problem. "Any number of things can make a tooth begin to grow crooked, and it will get worse and worse over the years if you don't keep it looked after."
Regular, knowledgeable dental care throughout a horse's lifetime will pay off handsomely when he's in his golden years, say both Faragalla and Young. A horse whose teeth have been properly cared for in his youth will be far more likely to still have useable grinding surfaces when he is pushing 30, while one whose dental health has been neglected may show all the signs of a "geriatric mouth" even at a tender age. Young says, "There's no one age at which you start to see geriatric-related dental problems; it depends so much on how well they've been looked after. I did a five-year-old the other day whose lower premolar was right up into his top gum. And someone was supposed to have been (floating the horse's teeth) regularly! That was a geriatric mouth if there ever was one, and the horse was five."
Because dental problems tend to compound themselves in older horses, it's a good idea to have your veterinarian assess your geriatric equine's teeth relatively frequently. Schedule an examination about every six months, or any time that you notice your horse dropping quids of feed, having difficulty chewing, or losing weight. If he's still being used as a riding or driving horse, pay attention to his attitude under saddle or in harness. A sudden resistance to bending in one direction, picking up one canter lead, or going up or downhill, for example, might be a tip-off that all is not well in his mouth.
Occasionally, a geriatric horse can suffer from some lingering soreness in his mouth after he's had dental work done. Young suggests the administration of a non-steroidal anti-inflammatory such as butazone if that's the case; and if the procedure involved the cleaning up of an infection or extraction of a loose tooth, a course of antibiotics also might be prescribed.
"They'll be a little sore because you've rattled their teeth around somewhat, and they just don't have a great length of root," he says. He added that most horses, however, need surprisingly little time to adjust to their altered dentition, and pick up right where they left their hay once they shake off the sedative.
A Dental Diet Plan
If your horse lives long enough, he might eventually run out of teeth, despite your attentive care to his dental health. If or when your veterinarian notes that his ability to chew is becoming limited, you'll want to make some changes to his diet to help him continue to eat and maintain good condition. Faragalla makes several recommendations to his clients with geriatric horses, including a switch from a timothy or coarse alfalfa hay to a finer hay such as coastal Bermuda or orchard grass. He also suggests a high-fat diet, "to get more calories into these guys," preferably based on flax seed (a.k.a. linseed) meal or feed-grade linseed oil, both of which have a high concentration of fatty acids that act as free-radical scavengers and can help reduce everyday cellular damage in the tissues of an older horse. Corn oil, he says, is a second choice, although it doesn't contain the same concentration of these fatty acids.
If your horse is nearly toothless and long-stemmed hay is too difficult for him to handle, Faragalla suggests alfalfa pellets (which can be soaked in water to make a mush) or chopped, packaged hay such as Dengie or A&M (alfalfa and molasses, a popular feed on the West Coast). Grain rations designed for geriatrics are a useful choice as well, although he notes that many are higher in protein than an older horse needs. (Look for one with a crude protein of about 10%, rather than 13% or 14%, he says.) The addition of a probiotic supplement can help encourage more efficient digestion of nutrients, and feeding vitamin B complex can also be helpful for older horses, which don't manufacture as much of these vitamins in their guts as they did in their youth.
Finally, Faragalla suggests that you evaluate your horse's selenium levels with regular blood tests (selenium is closely tied with vitamin E in the maintenance of the immune system). Because of its low toxicity level, however, selenium should not be supplemented unless you are sure your horse is deficient and that the soils in your area do not have high levels of this mineral already.
With the benefit of good dental care from a professional, a carefully chosen diet, and a little TLC, your geriatric horse should have every chance of maintaining good flesh and enjoying his feed for some time to come--even if he is somewhat long in the tooth.
About the Author
Karen Briggs is the author of six books, including the recently updated Understanding Equine Nutrition as well as Understanding The Pony, both published by Eclipse Press. She's written a few thousand articles on subjects ranging from guttural pouch infections to how to compost your manure. She is also a Canadian certified riding coach, an equine nutritionist, and works in media relations for the harness racing industry. She lives with her band of off-the-track Thoroughbreds on a farm near Guelph, Ontario, and dabbles in eventing.
POLL: Enriching Your Horse's Environment