External parasites including house flies, âfriendlyâ flies, stable flies, horse flies, deer flies, bot flies, mosquitoes, culicoides, lice and ticks are not only annoying, to your horse, but can be downright dangerous. Controlling these parasites leads to greater comfort and health for your horse.
External parasite control for horses
External parasites including house flies, "friendly" flies, such as stable, horse, deer, bot flies, mosquitoes, culicoides, lice and ticks are not only annoying, to your horse, but can be downright dangerous.
© 2013 by Carien Schippers
Methods for controlling these external parasites vary, according to the individual parasite.
Non-biting Flies
House flies and âfriendlyâ flies (those large, striped flies seen the past few years; their larvae are parasites of Tent caterpillars) have lapping mouth parts and so donât bite, but annoy horses by landing on them. Horses may continually stomp their feet which can lead to lameness issues. The flies can also cause conjunctivitis by landing and feeding around their eyes. House flies lay their eggs on manure and other decomposing organic matter.
Biting Flies
Stable flies, horse flies and deer flies are biting flies. In addition to annoying horses by their mere presence, their bites can be very painful and irritating, sometimes causing large, oozing lumps at the site of the bite. Stable flies lay their eggs on manure and decomposing organic matter, horse and deer flies lay their eggs in masses on plants near water.
Bots
Bot flies are the adult phase of the internal bot parasite. The bot has no feeding mouthparts and thus is unable to bite. It annoys horses by following horses around, laying many tiny yellow eggs on the horseâs legs, face and body. The horses chew on the eggs, causing them to hatch, starting the internal part of the botâs life cycle.
Mosquitoes and Culicoides
Itâs not just about the itch that accompanies a mosquitoâs bite. Mosquitoes can carry West Nile Virus, and Eastern or Western Encephalomyelitis, all of which can be fatal. People can also become infected with these diseases. Mosquitoes lay their eggs in still or standing water.
Some horses are extremely allergic to Culicoides bites. They have a systemic reaction in addition to reaction at the site of the bite. Their manes, tails, and faces are usually involved, with rubbing and hair loss the primary signs. Some are so allergic that their entire bodies become involved. Culicoides lay their eggs in still water, similar to mosquitoes.
Lice
There are two types of lice that affect horses; biting and sucking. Both types complete their entire life cycles on the horse. The biting lice are more common, and they can cause intense itching as they feed on the horseâs skin. They attach their tiny eggs to the horse's hair, most commonly near the mane.
As their name implies, sucking lice suck blood, and in large numbers, can kill a horse.
Ticks
Ticks are becoming an increasing problem in some areas. They have a long, multi-stage life cycle, during several stages of which may attach themselves to horses. Several species over winter on mice. Ticks are important external parasites in that they can carry and transmit both Lyme Disease and Anaplasmosis.
Strategies for control of external horse parasites:
Primary control of all external parasites includes limiting or eliminating breeding sites. This means eliminating standing water such as unused water tanks, old tires, low and swampy spots where mosquitoes, culicoides, horse and deer flies may breed on or near.
Parasitic wasps
The use of tiny parasitic wasps to kill the flies in the pupal stage has proven to be a very effective control method, especially if started before fly season. Trapping of adults prior to egg laying is another method of control. Fly traps, such as the Red Top, are quite useful in attracting adult house, stable and some horseflies.
Fly sheets and other coverings
Fly sheets and leg coverings, including entire body-covering sheets for those allergic to culicoides, provides additional relief. Keeping horses stabled during high fly season also is helpful. Stable, horse and deer flies feed primarily during the day. Culicoides and mosquitoes feed primarily at dusk, dawn and during the night. They are also weak fliers, so keeping a horse in a stall with a fan on creates enough of a breeze to significantly reduce these tiny insects.
Other products
Most horse owners know from experience that most spray products donât last as long as labeled for. Spot-on types of products for long-term fly control are proving to be more satisfactory in fighting external horse parasites. They last for 10-14 days, and fly sprays can be used with them to improve fly control while riding.
Several products say that they also control ticks. These include Buzz Off and the Repel-X. DEET-containing products marketed for humans also control ticks, and while not labeled for use on horses, they have been reported to be safe and effective at controlling ticks.