Hives (urticaria)
What it is: A skin manifestation of an allergic reaction to various triggers, including insect stings/bites, chemicals, medications or, less commonly, ingested or inhaled substances. In some horses, hives develop or worsen with pressure, heat, sunlight or stress. The exact causative factor is often a mystery.
Symptoms: Multiple round, raised areas on the skin (1/2 inch to 8 inches in diameter), usually with flattened tops and often occurring on the back, flanks, abdomen, neck and chest; variable itchiness; and respiratory difficulty (rare). Hives usually appear and disappear suddenly.
What to do: Hives are not usually an emergency, but you should call your vet immediately if your horse has difficulty breathing or has severe itching (rare). If you know what caused the reaction, eliminate it from your horse’s environment, if possible.
Outlook: Hives will recur if the horse is re-exposed to the allergen that caused them, so allergen avoidance will prevent further episodes. Unfortunately, it’s not always easy to determine the triggering allergen, so most cases of hives are treated symptomatically.
Back to Horse Health Glossary
This article originally appeared in the 2012 issue of Horses USA. Click here to purchase the most recent issue.
Plenty has been written about the prevention, causes, and treatment of founder, but less information…
Needles and horses usually aren’t anyone’s favorite mix, but if you’re around horses long enough,…
Horse ownership is daunting. The amount of information, opinions and different ways of doing things…
Antibiotic-induced clostridial colitis must be recognized and treated promptly to prevent a horse owner’s worst…
Read along for a guide on how to choose your riding helmet for safely riding a horse. Being a horse…
Read along for a look at each horse competing in the 2024 Kentucky Derby. In 2021, 17,779 Thoroughbred foals in…
Welcome to Horse Illustrated’s weekly installment of the Right Horse Adoptable Horse of the Week, offered in partnership with the…
Imagine an entire month dedicated to celebrating adoptable horses: For the past four years, the month of May has been…
Horses in the guest ranch industry come from varied breeds and backgrounds. Learn more about them. The scenery may be…
Thanks to a rail down by overnight leader Tom McEwen (GBR) on the 13-year-old German Warmblood gelding JL Dublin, a…