Q. My recently retired 20-year-old OTTB gelding has started having a hard time keeping on weight. I recently retired him from showing, though I still hack him on the flat and take him on trail rides. I’m especially concerned about him as winter approaches. Why is this happening and how can I help him?
Kathleen “Katie” Young, PhD
A. The first step in figuring out why your horse is having trouble maintaining appropriate body weight and condition is to examine your overall feeding program to see if he is receiving a diet that is adequate to meet his energy requirements and that he is actually consuming as much as you think he is. Dietary requirements (energy and nutrients) are determined by many factors including breed, sex, age, activity level, reproductive status, housing and health status.
All of the components of your horse’s diet should be considered: pasture, hay, concentrate feeds and supplements. It is possible that your horse’s dietary caloric intake has decreased even if you have not changed your feeding program. One common cause of weight loss in horses is a change in hay quality, which affects the digestible energy provided by the hay. Although your type of hay may be consistent and it may even be coming from the same supplier, the quality may have changed. The maturity of the plant when it is harvested greatly affects its nutrient content, and local environmental conditions may have resulted in hay that is lower in energy and nutrient content. Your veterinarian or an equine nutritionist can help you evaluate your horse’s total diet to make sure that the combination of hay and feed is providing adequate calories and other essential nutrients to meet nutritional requirements. Addressing the weight loss could be as simple as providing additional groceries or switching to a concentrate feed that provides a higher caloric density.
If the diet you are providing to your horse is appropriate and you have observed that he is consuming everything, your next step would be to consult your veterinarian to evaluate your horse for parasite infestation, which can significantly impact his body condition. Drug-resistant intestinal parasites have become more common, and veterinarians are now recommending new strategies for parasite control. Periodic fecal exams to determine fecal egg count are suggested to help understand the parasite status of each individual horse. Deworming programs should be tailored to the type of parasites found, the parasite population’s susceptibility to particular deworming drugs, geographic location of the horse and the degree to which individual horses shed parasite eggs. Remember, though, that certain phases and types of parasites may not be reflected in a fecal exam. Pinworms, tapeworms and encysted small strongyles will not be diagnosed by standard fecal floatation exams, so your veterinarian may need to perform additional parasite screenings.
Dental deterioration is also a concern in older horses who lose body weight and condition. Horses have hypsodont teeth, which means the teeth erupt approximately three to four millimeters per year to compensate for the tooth wear caused by the grinding motion of chewing. As a horse’s teeth wear, they can develop abnormalities such as sharp edges, hooks and waves that interfere with the efficient grinding and processing of feedstuffs during chewing. Regular dental care is essential to maintain the horse’s teeth in good shape to chew properly. Your veterinarian may determine that your horse is not maintaining appropriate weight and condition due to a dental condition that can be addressed by routine dentistry.
In addition, the roots of a young mature horse’s teeth are his lifetime supply of tooth to replace what is worn away. As the horse ages, at some point there is not enough tooth to replace the wear, and he can no longer chew efficiently. If your horse is at an age at which there is no longer adequate tooth to erupt and replace what is worn or other dental conditions (such as missing teeth) exist that will inhibit proper chewing and grinding, your horse may require a change in diet. Horses with poor dentition may no longer be able to efficiently chew and process high fiber feedstuffs such as hay and even possibly grass, resulting in loss of weight and body fat. If that happens, the fiber and calories provided by forage in the horse’s diet must be replaced by appropriate dietary components that he is able to chew and process. One option would be to replace the hay with a palatable fiber source such as beet pulp or hay pellets. Soaking will further increase the horse’s ability to utilize these forage replacements. A commercially prepared senior horse feed is another option for older horses with poor dental condition. These feeds are formulated to include appropriate forage or roughage sources to partially or completely replace hay and/or pasture in the aging horse’s diet. Some geriatric horses have such compromised dental condition that they are not able to properly chew a well-designed senior feed. In these situations, it may be beneficial to add water to the feed to provide a mash or gruel, which will be even more easily edible for the horse with extremely poor dentition.
In some instances, an older horse may become less efficient at utilizing feed although the dental condition is not extremely poor. Part of the aging process is often loss of efficiency of the digestive tract due to decreased motility, digestion and absorption of nutrients. Offering a higher quantity of feed and selecting feed with more digestible and available nutrition becomes important in managing senior horses. If the horse is still able to chew well and process long stemmed forages, providing high quality hay and a calorie and nutrient-dense feed may be adequate to prevent weight loss. Frequently these older horses maintain condition well when good quality pasture is available, but struggle when fed the same feed ration with hay instead of fresh pasture. In such situations, providing a complete senior feed with high-quality, easily digested forage or roughage sources to replace some or all of the hay can be extremely beneficial in maintaining the horse’s body weight and condition, as well as meet nutrient requirements to support the aging horse’s lifestyle.
Finally, EGUS, PPID or other health or medical conditions can result in significant loss of weight and body condition, and there are nutritional strategies that may be beneficial to horses suffering from these conditions. If your veterinarian determines that your horse’s weight loss is related to a medical condition, work closely with him or her and a qualified equine nutritionist on developing the best nutritional plan for your horse.
Dr. Katie Young is the lead technical equine nutritionist with Purina Animal Nutrition. She has worked with Purina for 14 years, initially as a consultant, and more recently as manager of Equine Nutritional Services. Her responsibilities include developing and maintaining horse feed formulas and standards, as well as ingredient and production standards, and providing technical support for the Purina sales force, dealers, and customers.
Dr. Young earned her bachelor’s degree from Missouri State University, and her doctorate in equine nutrition and exercise physiology from Texas A&M University. Her research concentrated on mineral requirements of resting and exercising horses. During her there, Dr. Young served as a faculty member in the equine science section of the animal science department teaching courses in equitation, training, and horse management, was supervisor and coach of the TAMU Equestrian Teams, and a board member of the Intercollegiate Horse Show Association. Currently, she rides and competes in dressage and combined training. Dr. Young has worked as a trainer and riding instructor for more than 30 years, and continues do so in the Kansas City area.
This article originally appeared in the December 2014 issue of Practical Horseman.