Many veterinarians credit the modern horse's extended life span to the improvements in worm control introduced last century. This, in addition to improvements in nutrition, management and health care mean we see many horses living into the 20s and sometimes 30s.
Senior horses have specific requirements in relation to the impact and management of their worm burden.
- The senior horse's weakening immune system increases his vulnerability to intestinal worms. – studies have shown older horses shed more worm eggs in their manure than their younger counterparts, suggesting heavier worm burdens.
- Intestinal worms can scar and cause chronic mucosal damage of the intestines, which affects nutrient absorption.
- The presence of worms also causes a decrease in nutrient absorption because the parasites compete for nutrients.
Craig Reinemeyer, DVM, PhD, a parasitologist at East Tennessee Clinical Research says: ‘As the gut and the kidneys' functions diminish with age, older horses often experience difficulty in maintaining normal protein metabolism. Since the major impact of a heavy worm burden is protein loss, the impact of worms could be greatly exaggerated in senior horses.’
Whatever the age-related responses to parasites may be, keeping worm burdens at minimum levels remains a paramount health concern throughout horses' lives – even more so when they are older.
A worm control program should be put into place to protect the older horse against the risk of ill health, either directly or indirectly related to worm damage, by removing worms from his internal system (with wormers) and removing worms from the pasture he grazes (pasture management & horse husbandry).
If worms cannot be removed completely from the pasture then you must provide an adequate ongoing worming program or provide regular monitoring of your senior horse for worm burden, through analysing their faeces for worm eggs (a fecal Egg Count or FEC) and worm accordingly.
The worm control program of the geriatric horse needs to be vigorous, and routine worming should be considered as an integral part of a health care program. If the horse is kept in a high-risk environment then then consideration to the shortest time between wormers must be used.
EasyWormer offers a Senior Horse Rotational Worming Program which delivers wormers at the right time of the year to help protect Senior horses against illness from worms. We also offer Fecal Egg Counts and a combined Fecal Egg Count and Wormer program.
- Older Horses Part 3: Vaccinations and Deworming The Horse Magazine:Sept 2007
- Caring for Older Horses: What you need to know. Dr Elizabeth Tee: registered specialist in equine internal medicine, Sydney University Veterinary teaching hospital Camden.
- Geriatric (Older) Horse James M. Casey, D.V.M, M.S. Equine Sports Medicine, Dentistry, & Surgery.
- Taking Care of the Senior Horse November 1, 2000 By Dr. Kathleen Crandell.
- Vaccines, Dewormers, and Nutrition for Senior Horses by Amanda Adams, PhD, assistant research professor at the University of Kentucky’s Gluck Equine Research Centre. Appeared in The Horse Magazine.