Texas Equine Veterinary Association

www.texasequineva.com • 14 of the barn, but rather at a distance away from it. • Install fans (ideally commercial-grade, but box fans should suffice) with a strong airflow in stall alleyways and windows since Culicoides are weak flying insects; heavy air currents make them incapable of reaching a horse. Along the same lines, fine screens can be placed in the barn as a barrier between insects and horses. • Avoid stagnant water accumulation around the barn and on the premises (where applicable) by improving "run-off" and drainage, since many flies breed/lay eggs in water. Specifically, avoid leaving buckets open to the elements outside. Likewise, change trough water as frequently as possible. Overall, try to keep horses and barns away from stagnant, running, or bodies of water. When this is not possible, Pre-Strike Mosquito Torpedo (Wellmark International) or goldfish can be added to the water where mosquitoes are a problem. • Fly Predators (Spalding Laboratories) contains beneficial insects that eat the immature stages of many of the insects that irritate horses. Sprinkle this product on manure areas every 3-4 weeks to help control pesky insect populations. • If an illuminated electrocution-style fly trap is used, place it away from the barn so it does not attract insects to stalled horses. • Ideally, horses should be separated from cattle. Limiting Fly Bites with Insecticides and Insect Growth Regulators • Prior to using any product on the horse's skin, try using a small amount of it in a sparsely haired region such as the armpit/girth to see if the product irritates the skin prior to applying it all over the skin. Always read label directions before administering/using a product. • The routine and diligent use of topical permethrin or citronella- based hand-pump fly/insect sprays (current brands on the market typically do not have enough permethrin in them for insect- sensitive horses) or spot-ons is paramount in itchy horses with insect allergy! Ideally, all stalled horses should receive some form of fly protection to help decrease the overall fly burden. Sprays are generally used over the entire body multiple times a day. Fly sprays should be applied at least 2-3 times daily and reapplied any time the horse is wet (sweat and/or bathed/rinsed). Spot- ons are generally applied once every week since they are more concentrated—read label directions and apply the product quickly in streaks or spots preventing it to concentrate/pool up in a single area, which may be irritating to the skin. For severely affected horses, improved control can be better achieved with the use of a spot-on and the periodic use of a hand-pump spray on days in between spot-on application. It is important to note permethrin- based products are toxic to cats; do not use them on any barn cats! • Skin-So-Soft (Avon) diluted 50:50 with water and sprayed or sponged onto the horse may be an additional repellent measure to hand-sprays and spot-ons as described above. • SWAT Fly Repellent Ointment (Farnam) may be used around open wounds to reduce the attractiveness of the wound to insects. Additionally, it may be applied to the backside of horse's ears when "fly strike" is an issue. • Fly sheets and masks may be needed for severely affected horses. Several of these barriers are now impregnated with insecticides. Amigo Bug Buster with Insect Shield is a rather lightweight sheet that does not retain much heat. • Automated fly spray/repellent systems in the barn are expensive, but their use is another strategy at limiting flies in the barn environment. In order for these systems to be effective for the insect-allergic horse, they must be used in conjunction with spot-

• Cover