Leptospirosis is a bacterial disease of worldwide distribution that can cause illness in many species of mammals, including people. In horses, leptospiral infection has been associated with kidney failure, pregnancy loss, and equine recurrent uveitis, which can lead to blindness. Horses become infected with leptospirosis through contact of mucus membranes or broken skin with infected water. The kidney is the target organ of the bacteria, and the horse can spread the disease through infected urine. Disease may be asymptomatic, limited to mild fever and malaise, or may cause acute renal failure, uterine infections leading to abortion in mares, or recurrent bouts of uveitis that may affect one or both eyes.
Until recently, control measures for leptospirosis in horses were limited to providing access to clean drinking water, vaccinating other susceptible in-contact animals such as cattle and dogs, and using ruminant vaccines off label. Recently, an equine specific vaccine was introduced (LEPTO EQ EQ INNOVATOR ®) to protect horses against Leptospira pomona, which is reported to be the species of leptospirosis most commonly associated with clinical disease in horses. This vaccine may be especially helpful broodmares, horses with access to ponds or other natural water sources, and horses with equine recurrent uveitis. Please contact your veterinarian to learn more about whether your horse would benefit from this vaccine.