There are many reasons owners keep older horses beyond their usefulness. Some have an emotional attachment; others are valuable breeding stock. Some horses have second careers and make safer mounts for youth and beginners. It takes a long time to train a horse that is safe, trusting and knows its job.
So, when is a horse “old?” Age 15 seems to be the cutoff for insurance purposes. On average, a horse under 15 years is insured at 3.4% of its value. After age 15, insurance rates increase to 5.25% of the horse's value. In addition, loss of major medical and use insurance is difficult to get.
Why age 15? Some general signs of aging increase in horses in their mid to late teens. This may include graying and rough hair coats, decreased muscle and skin tone — basically the same physical aging signs that humans experience. As one year of a horse's life equals three years of a human's life, a 20-year-old horse is chronologically equal to a 60-year-old human.
Older horses are less active, have structural and dental problems. In addition, conformational changes — a low back and facial changes (hollowing of the eyes) — generally begin.
Such horses begin to show metabolic signs of aging, such as decreased feed efficiency, endocrine problems, and decreased kidney and liver function. They develop pituitary tumors, melanoma and respiratory diseases. Older horses develop such hormonal problems as hypothyroidism, Cushing's Syndrome, adrenal exhaustion and diabetes.
Most often reported is Cushing's Syndrome (excessive cortisol secretion). The symptoms include a long, rough hair coat, failure to shed, slow-healing wounds, loss of muscle mass, excessive water consumption and urination, laminitis and increased blood sugars.
Management's the answer
Geriatric horses need more management consideration. Work out a health schedule with your veterinarian; aging can compromise an older horse's immune system. Regularly float teeth, and hoof care is a must to keep older horses sound.
The most difficult consideration, however, is feeding. In healthy horses (good body condition) with good teeth, feed a normal ration of hay and whole grains — the same as fed to other horses. In determining the diet of a geriatric horse, consider its weight, activity and the work it performs.
Good-quality hay (plus salt/minerals) is sufficient feed for a mature, healthy horse that's ridden very little. With an increase in work (and, in some cases, age), grain should be added to its diet.
Some horses are easier to feed and require fewer nutrients than others. Others require special attention. It's important to know how to feed your horse and to make sure it gets the needed nutrients.
If your geriatric horse has bad teeth, processed grains and forages (alfalfa pellets), may be needed, along with the regular ration. For horses with severe tooth damage, utilize processed feeds such as chopped hays, pelleted, crimped and/or extruded diets. For horses that can't chew, use mashes (mix a pelletted complete feed in water) at 1.5-2 lbs./cwt., but don't feed bran mash. It's too fibrous, bulky and inverts the calcium: phosphorous ratio.
The biggest challenge is feeding geriatric horses without teeth, or with severe tooth damage. Feed a slurry of complete pelleted feed and/or mashed alfalfa pellets. Add some long-stemmed, soft, leafy alfalfa hay.
Even toothless horses want to chew fiber. Supply fiber in all older horses' diets — soft hay or even beet pulp — an excellent fiber and energy source. Soaked beet pulp is digestible, chews easily and is a good calcium source.
All horses chew in a circular motion, which eventually forms sharp points on the molars. These can cut their cheeks, a painful development that hampers chewing. Prevent these by “floating” the teeth, which involves filing the sharp points down. Have your veterinarian check and float your horse's teeth annually.
Some added feeding tips:
Because a horse stomach is very small and can't hold a large amount of feed at one time, feed 3-4 equal meals/day, or at least twice/day on a regular schedule. Don't overfeed — it can cause digestive upsets.
Feed highly digestible feeds and good-quality forage. Color is an indicator of quality and nutrient content. Good hay is a bright green, leafy and fine-textured, with a fresh pleasant aroma. Most of hay's nutrients are in the leaves.
Watch for mold, dust, weeds and other foreign material in hay. Avoid dust in any horse feed. Over time, inhaling dust results in chronic obstructive pulmonary disease, or heaves. Sprinkling or dunking questionable hay in water can reduce dust, but it's best to always avoid moldy or dusty hay.
Feed special-needs horses individually if necessary. Ensure older horses get to eat their rations and the boss horse isn't taking it. Make any ration change gradually (over a minimum of five days) to prevent digestive disturbances.
If your hard-keeping horse won't eat enough calories, add ¼ to ½ cup of oil (corn or vegetable) to the grain. Due to decreased feed efficiency, some research indicates geriatric horses may need to be fed similar to the NRC requirement for yearling and weanlings (vitamin and minerals).
Feed a high-quality protein, 14%. Add vitamin C if a compromised immune system is suspected (supplement vitamin C at 5-10 g/day). B vitamins can be fed for pituitary tumors (Cushing's Disease) and liver disease. A good vitamin B source is brewer's yeast; it improves feed utilization and health of the gut microflora.
Some commercial “older horse feeds” use chelated vitamins, a process where vitamins are attached to proteins, making them more available to the horse. Another process is extruded feed (uniformly mixed feed similar to pet food processing). These processes help older horses better absorb their feed.
Special diets for older horses
When caring for a horse with confirmed kidney failure, feed a low-calcium diet (less than 0.45% of the overall ration), and low protein and phosphorus (below 10% and 0.3%, respectively).
A horse with signs of jaundice, weight loss, lethargy, appetite loss and intolerance to fat and protein in the diet may be suffering liver failure. In contrast to kidney failure, such horses need more sugar to maintain blood glucose levels. Emphasize carbohydrates and feed lower protein nad fat levels. Because the liver is a site of B vitamin synthesis (especially niacin) and vitamin C, supplement with oral B complex (about 5 cc/day) and ascorbic acid C.
Remember, some exercise improves appetite, digestion, muscle tone and mental health for horses, so keep your older horse active. With a little extra care, your geriatric horse can continue to lead a healthy and productive life.
Ann Swinker is an Extension horse specialist at Pennsylvania State University in University Park.