There’s good news for owners of senior horses: Finding the “ideal” ration to keep the aging horse healthy and at an appropriate weight doesn’t have to be rocket science. In fact, his ration might not even need to change just because he’s got a few more gray hairs around his eyes. Still, owners should consider some key points when feeding their seniors.

Sarah Ralston, VMD, PhD, Dipl. ACVN, shared her tips for feeding senior horses at the University of Kentucky’s senior horse care mini-symposium, held Sept. 28, 2017 in Lexington. She recently retired from her long-held post as a professor in the Department of Animal Sciences at Rutgers, The State University of New Jersey, in New Brunswick.

“Many senior horses (more than 20 years old) are healthy, happy animals that do not need any special nutrition or care,” she said.

If a healthy older horse is thriving on the ration he’s been consuming for years, there might be no need to change it solely because he’s reached a certain age.

“If (the diet) ain’t broke, there’s no need to fix it!” Ralston said.

Geriatric horses, however, might benefit from dietary adjustments. There’s an important distinction between old and geriatric horses, Ralston stressed, as the former term refers to chronologic age and the latter means a horse has one or more health problems. But first, take the time to carefully evaluate the horse’s current health status and diet, she said:

• Evaluate the horse’s current rations and the nutrients they provide. Generally speaking, healthy senior horses might require higher levels of protein, phosphorus, and restricted (but not below normal) calcium and crude fiber than younger, mature horses, Ralston said. If you’re unsure whether your horse’s current diet meets his needs, consult an equine nutritionist or your veterinarian for help;
• Determine whether he is over- or underweight. Of course, this will determine whether your aging equid needs fewer or more calories in his diet;
• Have his teeth thoroughly examined to identify any abnormal dentition. Ralston specified that your veterinarian should perform a full mouth exam with a speculum to ensure potential issues, such as hooks on the back molars and missing molars, aren’t overlooked. Poor dentition can reduce horses’ chewing ability, which can lead to an increased choke risk or reduced nutrient intake.
• Before changing to a “senior” type ration, consult your veterinarian to determine whether your horse could have kidney or liver dysfunction, both of which are not uncommon in older horses, Ralston said, and can impact an ideal ration significantly;
• Ask your vet to check your horse’s pituitary and thyroid function. Horses with thyroid or pituitary dysfunction could have reduced glucose tolerance and/or low vitamin C levels and, as such, could require a different ration;
• Ensure the horse is on a regular deworming schedule. Ralston said her research in the 1980s and ‘90s suggested that chronic gastrointestinal (GI) tract scarring due to parasitic infection could lead to reduced phosphorus and protein retention but that since the release of modern oral dewormers in the 1970s, the GI tract scarring seems to be less prevalent and, therefore, less of an issue. “However, more recent research has shown that horses over 20 years of age that are geriatric do not respond as well to dewormers and should be monitored more carefully,” she said;
• Take a close look at social environment; if the horse has lost weight, it could be the result of getting chased away from feed by other herd members. Simply separating horses at feeding time could help ensure they’re each consuming their allotted rations (and no one else’s).

Ralston also noted that older horses, especially those with arthritis, tend to thrive on movement. She advised against keeping them stalled or confined to small spaces for long periods, unless prescribed due to another medical condition. Also, older horses tend to be less tolerant of temperature extremes, so ensure they have adequate shelter, she said. Shelter from wind and snow in winter (run-in sheds, wind blocks) and high heat (shade!) in the summer will help, she added.

Feeding Recommendations

As discussed, healthy old horses don’t necessarily require a diet that’s substantially different from what they’ve been consuming throughout their adult years. But if they are not doing well on their current rations and after a thorough veterinary evaluation, Ralston recommended:

• Choosing a pelleted, cubed, or extruded concentrate that is forage-based, but formulated for senior horses;
• Avoiding textured sweet feeds (primarily processed grains with added molasses) for old horses with metabolic issues; and
• Providing free-choice forage and/or hay, “as long as horses’ dentition allows for it, even if it is on the ‘senior’ complete ration,” she said. “Horses like to chew!”

For otherwise healthy horses with dental issues, she said to consider adding easy-to-chew alternative fiber sources to the diet, such as:

• Soaked hay cubes or pellets, or
• Soaked beet pulp.

Some senior horses might benefit from these supplements, said Ralston:

• Vitamin C (0.02 gm/kg body weight) might benefit horses with compromised immune function (chronic skin infections, hoof abscesses, etc.); however, it shouldn’t be supplemented without careful consideration. “Once (vitamin C supplementation is) initiated, it will need to be continued for life or tapered off very slowly,” she cautioned.
• Vitamin E (500 to 1,000 iu/day) might benefit horses without access to fresh forage (such as grass) and those suffering from recurrent infections.
• An anti-inflammatory product and/or glucosamine/chondroitin sulfate supplement might benefit horses with arthritis issues. Discuss these with your veterinarian.

Senior horses with kidney and liver dysfunction have more specialized dietary requirements:

• Kidney dysfunction—Limit calcium and phosphorus intake in horses with kidney issues to only their normal daily requirements (consult your veterinarian or equine nutritionist to find out how much your horse needs), and keep their protein intake at 10% of their total if they have elevated blood urea nitrogen concentrations. At the same time, increase their vitamin D intake (as the kidney is less effective at synthesizing it) but keep the dose to 500 iu or less per day, Ralston said.

  Feed grass hays without significant legume (alfalfa or clover) content and concentrates containing corn, oats, barley, and/or molasses (contrary to what is recommended for a healthy older horse, she noted), and add oil to the diet if horse needs more weight. Also avoid beet pulp and bran, she said.

• Hepatic dysfunction—Horses with liver failure require a diet higher in soluble carbohydrates (i.e., grain-based concentrates; again, she noted, this is contrary to what’s recommended for healthy older horses) and the vitamins niacin and vitamin C (which are synthesized in the liver). In addition, the ration should be lower in protein (8-10% of the diet) and fat (less than 5%) than the average older horse, Ralston said.

With All That Said…

Yes, specific rations benefit older horses with certain health issues. However, Ralston said, “it’s better to feed a less-than-ideal ration than to feed nothing at all.”

Some senior horses are notoriously picky about what they eat, she said. So, for example, if the horse with kidney dysfunction turns his nose up at grass hay in favor of alfalfa, or the one with liver problems will only eat one feed that happens to contain soybean meal, it’s better to let them eat what they will rather than drop weight because they’re not a fan of the perfect ration.

If you have questions about feeding your senior horse, work with your veterinarian or an equine nutritionist to developing a program that will meet his nutrient needs.