I’m old enough to remember when a 10-year-old horse was considered aged. Advances in health care and a growing respect for the value of experience and a mature temperament have changed that. Many horses are now active into their late teens or 20s and may live for a decade or more beyond that.
However, time seems to take an inevitable toll on any species. Are there special nutritional needs for the senior horse?
There is nothing you have to change simply because of the horse’s age. If he is holding weight well, looking good and has good energy, don’t change a thing. That said, there are some things to look for as the horse ages.
Dental care is often emphasized for keeping older horses in peak condition but the truth is there are many seniors whose teeth show no obvious issues but they begin to lose weight. This is likely because the angle of the chewing surface, and the force that can be generated, changes with wear and dental work. A typical history is that they do fine on pasture, which is soft and easy to chew, but will lose weight on hay.
Some of these horses only need a switch to chopped hay. Others will respond to a diet of pelleted hay and concentrate, preferably fed well soaked or even soupy. Hay should still be fed for chew time, but the horse will need from 50 to 100% of his calories to come from the soaked foods.
Older horses often have a reduced number and diversity of microorganisms in their hind gut. This issue may actually overlap with the chewing problems above since fibrous feeds need to be well processed for fermentation to be efficient. Signs of this issue may include lean body condition, abdominal distention, soft manure or fluid released around fecal balls.
Chopped or ground hays are actually prebiotic since they give the organisms something they can more easily process. Highly fermentable fiber sources such as beet pulp, psyllium husk, soybean hulls and complex plant carbohydrates boost the prebiotic value. High potency probiotic supplements can also help – but only after their “food” in the form of prebiotics above are already in place.
You may hear that older horses need more protein but their requirements are actually not different. It’s their ability to utilize the protein that may change. In other species, age may come with reduced production of stomach acid which is called achlorhydria. Stomach acid plays a key role in the first step of protein digestion. Production of digestive enzymes by the pancreas may also drop with age.
None of this has been specifically investigated in the horse but provision of digestive supplements with protease activity and adding vinegar to meals may help a horse that seems to be losing muscle mass. It is also important to regularly check for PPID – pituitary pars intermedia dysfunction, aka Cushing’s Disease – because this is a common disorder of older horses and muscle loss is a hallmark. Additionally, regular exercise has been found to be protective against the muscle loss that naturally accompanies aging.
Correct mineral nutrition may be as important for the senior horse as the very young horse. While issues such as decreased bone strength and waning immunity have their roots in hormonal changes and DNA decay, they can be greatly worsened by mineral deficiencies and imbalances. Of all the factors, this is the one that is completely within our control.
Aging appears to be accompanied by a reduction in all the body’s basic ‘housekeeping’ functions such as production of vitamins, enzymes and antioxidants. A well rounded vitamin supplement is therefore cheap insurance and of more importance for older horses.
There’s no reason today’s horse cannot enjoy good health well into his second decade. Nutrition plays an important role in this and gives us a powerful tool for supporting the senior horse.
Eleanor Kellon, VMD