Written by: Thomas Lenz, DVM., M.S., DACT
Ticks are becoming an increasingly significant parasite of horses across the United States. Some blame it on global warming, while others believe the increase in deer and other wildlife populations has resulted in ticks becoming more prevalent.
Ticks cause localized tissue irritation, when can result in the horse constantly rubbing on trees or fences; hair coat damage; and anemia due to blood loss. Ticks also transmit a number of serious diseases including piroplasmosis, lyme disease, equine granulocytic anaplasmosis (ehrlichiosis) and equine infectious anemia. Ticks are not species-species specific, so the same ticks that feed on your horse can also feed on your dog or you.
Ticks are blind and find their hosts by detecting ammonia, which is given off by a horse's breath and body during sweating or by sensing heat, moisture and vibrations. A tick waits for a host by resting on the tips of grasses and shrubs with its first pair of legs outstretched. When a horse brushes by, the tick quickly climbs aboard.
Some ticks attach immediately while others wander around the horse's body, looking for the areas where the skin is thinner. That's why ticks are most often found on a horse's chest, underbelly, mane, tail or inside the flank. The result is often a local skin reaction that appears as a small, firm nodule.
Once filled with blood, ticks drop off to molt and progress to the next stage of their life or in the case of adult females, lay eggs.
Tick prevention requires diligence to locate them on your horse and remove them, application of tick-specific repellents, and environmental controls. Coumaphos spray or powder; permethrin applied as a wipe, spray or spot-on; and zeta-cypermethrin dusting powders are the most common repellents, which should be applied to the horse's mane, tail head, chest and underbelly. You don't really need to spray the entire horse.
Which repellent you choose to use, the labels should be checked to make sure they are effective against ticks, as many insect repellents are not. Apply them before riding or turning your horses out on pasture.
Check your horses for ticks thoroughly after a ride and at least daily if they are out on pasture. Often it is easier to feel ticks than see them. Run your fingers over the horse's skin in areas where ticks like to attach, feeling for small bumps that may indicate smaller immature ticks.
Should you find a tick on your horse, remove it immediately:
- Do not crush or twist the tick, as it causes the tick to regurgitate blood back into your horse, which increases the chance of infection or disease transmission.
- Do not apply baby oil or petroleum to smother the tick, or force it to detach with a lit match. Those methods do not work and can cause damage to your horse.
- Wear gloves and use tweezers to gently remove the tick.
- Grasp the tick firmly by the head where it enters the horse's skin.
- Do not squeeze or yank. Instead, pull firmly and steadily straight away from the skin until the tick's head comes free.
- Drop detached ticks in a small jar of rubbing alcohol to kill them. Wash the attachment site with a mild antiseptic and then wash your hands.
From a pasture management perspective, you can decrease the number of ticks your horse may pick up by removing brush where ticks like to live and discouraging wildlife such as deer that tend to reintroduce ticks to grazing areas. Guinea fowl or free-range chickens do an excellent job of finding and eating ticks around the barn yard. If you have questions on tick control or the diseases they can transmit to your horses, talk to your local equine veterinarian.
Article provided courtesy of AAEP Alliance Partner, AQHA.
About the author: Thomas R. Lenz, DVM, M.S., Diplomate of the American College of Theriogenologists, is a trustee of the American Horse Council, past chairman of AQHA’s research committee and past president of the American Association of Equine Practitioners.