Our horses are living longer now than ever before. Improved parasite control, better nutrition, and advances in veterinary care combine to give us more days with our animals and improve the quality of their lives as they reach their third and even fourth decades. In fact, an estimated 20% of horses in the United States are over the age of 15.
It's good news for us. We get more years with our horses, and our horses live longer and more productive lives. But as our horses age and their bodies start to fail, we have the obligation to meet their changing nutritional needs. Older horses with problems (geriatrics)--whether they are hard keepers or suffer from metabolic diseases or painful unsoundness--deserve the best nutrition we have to offer.
When it comes to feeding geriatric horses, "One size doesn't fit all," says Joe Pagan, PhD, president of Kentucky Equine Research, an equine nutrition research and consultation company based in Versailles, Ky. Meeting those individual needs of your geriatric horse is up to you.
Describing the Geriatric
Just because a horse is old doesn't necessarily mean he's a geriatric. "Geriatric implies that there's a clinical problem," says Sarah Ralston, VMD, PhD, Dipl. ACVN, of Rutgers University in New Jersey. "There are an awful lot of horses out there that are 20-plus years old and do just fine on regular feed."
Geriatric, by definition, is a condition related to diseases and disorders caused by aging, not by a specific number of years spent on this earth.
"The horse owner needs to have a look at his individual horse and decide if he's really a geriatric," Pagan says. "A geriatric horse is actually a sick old horse, and most aged horses aren't necessarily sick. So, I think it's most relevant for horse owners to classify individual aged horses based on how well they maintain condition."
He points to U.S. Equestrian Team endurance team member Becky Harris' 18-year-old mare Honey as an example of a healthy senior horse. Riding Honey, Harris of Medina, Ohio, was one of two Americans to complete this year's Federation Equestre Internationale (FEI) World Endurance Championships in Dubai, United Arab Emirates (a 100-mile competition across the desert). She finished 20th overall.
"Is that a geriatric horse?" Pagan asks. "No, she's an elite athlete. A horse owner shouldn't use the calendar to decide if a horse is geriatric."
Pagan finds it useful to classify old horses into three categories:
1) The first, like Honey, are healthy senior horses. "Their nutrient requirements would be the same, I'd suspect, as a younger horse," he says. These seniors do not fit the definition of geriatric, and you should base their nutritional requirements on the nature of their training and level of regular usage.
2) The second group, hard keepers, includes geriatrics that struggle to maintain healthy body condition due to dental issues, gastrointestinal inefficiency, a compromised immune system, and/or stress caused by pain issues. "They're just hard keepers, and many of those horses are older and have special nutritional needs. Try to increase the energy density of feed, and possibly increase the digestibility through grain processing and adding more energy-dense nutrients (to their diet) such as fat," Pagan advises horse owners.
3) The last is the opposite extreme caused by geriatric conditions in which the geriatric horse becomes overweight. "These are obese older horses that have metabolic disturbances," Pagan explains.
The second and third groups of horses have special needs that horse owners and managers must address under the guidance of a veterinarian or equine nutritionist. Pagan recommends classifying your older horse into one of these categories before making decisions about his special needs. If your horse does fall into a geriatric category, then take the steps necessary to address his individual problems related to aging.
The Hard Keepers
Old horses, even geriatrics, aren't supposed to be thin, says Ralston. But, Pagan points out, horses' bodies can and do change with age. Just as humans carry fat differently as they move through life stages, so do horses. A senior horse, especially an old broodmare, will often have a more prominent spine, wither, hip, and ribs than she did as a youngster. "If you palpate a little lower, she can actually be quite fat," Pagan says. "I think the visual interpretation of body condition by looking high on the topside of an old horse is misleading."
A veterinary examination and manual palpation of the horse's entire body to find fat deposits can help determine if your horse is underweight and identify the cause of any geriatric conditions. "If an old horse starts losing weight, there's some sort of medical reason why," Ralston says. "If you've got your 25-year-old campaigner, and he suddenly starts losing weight and not doing as well as he used to, the first thing you need to do before you change feed is have a thorough veterinary exam," Ralston says. "Make sure that his liver and kidneys are functioning and there's nothing else wrong."
Dental problems--As horses age, their teeth can deteriorate, and most horses' teeth stop erupting by the time they pass the age of 30. "They've erupted all the tooth they had," Ralston says.
For this reason, she recommends regular dental care every six months to preserve the teeth a horse has left. Your veterinarian or dental technician can also help alleviate any chewing pain caused by points on the teeth or other dental abnormalities.
"If the only thing wrong with a horse is his teeth, it's very easy now to keep these guys going," Ralston says. "You can use senior feeds that can be soaked to make a mash. I've also found that using soaked hay cubes works really well. Feeding a mixture of soaked hay cubes and soaked senior feed seems to hold them very well."
Soaking feed makes it easier to chew for the geriatric, can help prevent choking, and is a simple way to add water, a necessary nutrient that can help prevent impaction. Ralston also recommends feeding older horses several small meals, even four or five times a day, and not more than 0.5% of their total body weight in any given feeding. "Anything more is just too big of a meal for them to handle," she says. "In my experience, these horses will start going off feed if they're given too much at one feeding. And the best-balanced ration in the world doesn't help if he won't eat it."
Inefficient metabolism--"There's also the possibility that these horses have become metabolically less efficient," Pagan points out. "I don't think you can necessarily say, 'Oh, it's the old horse's teeth.' It can be more complex than that--there could be some issues with the ability of the GI tract to absorb nutrients."
Early nutritional studies of senior horses in the 1970s and 1980s suggested older horses didn't absorb nutrients as efficiently as their younger counterparts, but those studies took place before good deworming programs were a regular part of horse keeping.
"Chronic parasite damage to the gut can, in the long run, cause damage and lead to malabsorption," Ralston says. "But we did similar studies at Rutgers in the 1990s using horses that had had good deworming all their lives, and we didn't see the same problems with digestion."
Some geriatrics that didn't receive regular parasite control throughout their lives are simply less efficient at using energy from feed and forage and often benefit from calorie-dense feeds and fats added to their diets.
"Typically, their caloric requirement goes up," Pagan says, "and they just need more calories to maintain good condition."
Ralston recommends diets with protein up to 12-14% for geriatrics, and she warns against excessive amounts of calcium (from straight alfalfa hays) and phosphorus (from bran) for senior and geriatric horses, because the increased minerals can stress the kidneys.
"Alfalfa is way too high in calcium for these older guys," she says. "Stay away from bran mashes. They're very high in phosphorus, so you don't want to feed any (geriatric) horse a daily bran mash."
Timothy, high-quality grass hays, and 50% alfalfa mixes make good forage for older horses, Ralston says.
Geriatric horses can also become especially hard keepers during the cold months as they use energy to keep warm. The best thing for any horse in a cold climate is adequate access to forage, Pagan says.
"To keep a horse warm, they need a good hair coat," he adds. "But when they eat hay, the hay is fermented in the hind gut by bacteria, and that produces a lot of heat. That byproduct heat can warm the horse from the inside out. The idea of feeding more grain isn't really all that effective. They are going to eat the grain and shiver to make heat."
Chronic unsoundness--Constant stress on the animal, such as pain caused by arthritis, can also cause a horse to lose body condition due to depressed attitude and disinterest in eating, Ralston says. "Pain is a stress on their systems," she says. "Some old horses get to the point where they can't lie down because they can't get back up."
Pain management, glucosamine supplements, pasture turnout, and easy access to feed can help increase the appetites of these geriatric horses.
Fat and Unhappy
The opposite problem of weight loss in geriatric horses is that of weight gain. Sometimes obesity in the geriatric horse is caused by the owner overcompensating with feed for the possibility of weight loss in the animal. Metabolic problems, including pituitary gland tumors, can also cause weight gain, as can inactivity due to retirement or unsoundness.
"People look at an old horse that's ribby and think, 'Oh, it's thin. I need to feed it more,' " Pagan says. "If you try to cover up ribs and boniness with fat, you might end up with a grossly obese older horse."
No matter what the cause, carrying extra body fat can cause additional problems for the geriatric.
Metabolic issues--Age-related metabolic issues, including the condition described as Cushing's disease, pituitary dysfunction, thyroid tumors, or other hormonal and insulin-related disorders require special nutritional management under the supervision of your veterinarian and equine nutritionist. These geriatrics, in particular, might react negatively to senior feeds that often include high levels of energy-dense sugars, Ralston says, and they need to be carefully managed with a balanced diet.
"Typically, the idea (of senior feeds) is to reduce the fluctuation of blood-glucose levels," Pagan adds. "A feed that was formulated with less dependence on readily hydrolyzable carbohydrate and a greater dependence on fermentable fiber and fat may be more appropriate. The reality is that the senior feeds were designed by very clever marketing people. I think the rationale with the senior feeds was to capture a market niche as opposed to really, truly addressing a requirement. Most of the senior feeds are designed with three or four things in mind--a little higher protein, more phosphorus, maybe some yeast cultures for digestibility, and greater energy density. But that's really for the horse that's a hard keeper."
Feeds with low glycemic indexes are often better choices for horses with metabolic issues, he says. A glycemic index is the ranking of carbohydrate-containing feeds based on their impacts on blood-sugar levels, with low index feeds having less effect and high index feeds having more effect. Feeds with low glycemic indexes, such as stabilized rice bran, often contain high percentages of fat. Typically, feeds low in starch and high in soluble fat, whether specially formulated or mixed by the horse owner, work well for the geriatric horses with metabolic issues.
"There are a number of feeds that fit that category," Pagan says.
Chronic unsoundness--Chronic lameness can cause some horses to go off feed, as discussed in the section about hard keepers, but some horses just keep on eating despite themselves. "These older horses can get rather plump," Ralston says, "and it's not in their best interest."
Lack of physical exercise reduces a horse's caloric requirements, making it necessary to adjust his feed ration. If the ration isn't reduced and these horses no longer get regular exercise, possibly due to arthritis or navicular syndrome, then their bodies store unused calories as fat. That extra body weight becomes part of a vicious cycle by adding extra biomechanical stress and aggravating existing conditions, potentially causing more unsoundness.
Pagan stresses that low-starch diets are particularly important for horses with chronic laminitis. "They fall under the same category as the Cushing's horse in that you want to greatly reduce the amount of grain in their diets. You may have a double whammy with the older, chronically laminitic horse, because with the laminitic horse, you have to be careful about getting starch in the hind gut, whether it's a 3-year-old horse or a 30-year-old. Now, with the older horse, if it has a reduced enzymatic capacity to digest grain, then it's going to be even more susceptible to putting grain into that hindgut. So, for those guys, you need to be really careful about feeding them low-starch diets."
Making the Right Choice
In the end, no one knows your geriatric horse's needs better than you and your veterinarian. With the guidance of your veterinarian and an equine nutritionist, you can make the best feed decisions for your geriatric horse and help him lead a long and comfortable life.
OLD HORSE NUTRITION PROBLEMS: What Kind of Older Horse Do You Feed?
- Healthy senior horses basically have the same nutrient requirements as younger horses. Their diets should be based on the type and extent of their activity level; monitor horses closely for appetite changes.
- Hard keepers fight to maintain healthy body condition due to dental issues, gastrointestinal inefficiency, stress from pain, or a compromised immune system. Supplement an energy-dense nutrient, such as fat, for these horses.
- Obesity in the older horse can be caused by the owner overcompensating with feed for the possibility of weight loss. Metabolic problems and inactivity due to retirement or unsoundness can also cause weight gain.
About the Author
Michelle Anderson serves as The Horse's digital managing editor. In her role, she produces content for our web site and hosts our live events, including Ask the Vet Live. A lifelong horse owner, Anderson competes in dressage and enjoys trail riding. She's a Washington State University graduate (Go Cougs!) and holds a bachelor's degree in communications with a minor in business administration and extensive coursework in animal sciences. She has worked in equine publishing since 1998. She currently lives with her husband on a small horse property in Central Oregon.