Have you ever found your horse with unexplained bumps or swellings, sometimes with oozing, on his legs, body or muzzle long after bug season should be over' They’re probably spider bites.
Bites from nonpoisonous spiders are rarely serious but can be extremely itchy. The horse’s rubbing may open the area, risking secondary infection.
Don’t use creams or liquids on spider bites. The human spray Bactine or a liquid equine antiseptic/drying spray will do a good job of drying up the spots and relieving itch. If neither of these is available, try isopropyl alcohol or witch hazel. Bites on the lower legs can be soaked then wrapped with a clean cotton wrap, using an effective anti-chew product on the wrap if needed.
If bite areas enlarge or show hair loss, it may have been a poisonous spider bite. Alert your veterinarian right away as these bites require treatment or they will continue to worsen.
To make your horse’s stall as uninviting to spiders as possible, keep it clean and well swept. Don’t forget the areas behind and under feed, hay and water buckets. When the stall is cleaned, rake all the bedding away from the walls and toward the center and then fluff it well.
Pine shavings discourage spiders. If you prefer straw, use a thin layer of pine underneath and along all the edges. If these measures aren’t enough, consider a light spraying of insect repellent on the walls, corners and floors, even the horse if necessary, until the spiders leave.