Equine Leptospirosis Abortion Update from the UKVDL

Equine Leptospirosis Abortion Update from the UKVDL

The total number of cases in Kentucky is unknown, but the UKVDL receives a high percent of abortions that occur in the Bluegrass region.

Photo: Anne M. Eberhardt/The Horse

This reproductive season (June 2011 to present) the University of Kentucky's Veterinary Diagnostic Laboratory (UKVDL) has confirmed 21 cases (as of Feb. 17) of equine leptospiral abortion in the Central Kentucky region. This is the highest number of cases seen by the laboratory since diagnosing 31 cases in 2009-2010 and 40 cases in 2006-2007. Both outbreaks coincided with increased rainfall.

The total number of cases in Kentucky is unknown, but the UKVDL receives a high percent of abortions that occur in the Bluegrass region.

Equine leptospirosis is a bacterial disease found worldwide that affects many species, including horses and people. The source of the bacteria is the urine of wild animals including mice, squirrels, fox, skunks, opossums and deer. Other domestic species such as cattle, dogs, and pigs can also be sources of infection. Horses are infected when bacteria enters through the skin or mucosal membranes of the eye or mouth by contact with blood, urine, or tissues from infected animals. This infection can also occur when horses splash infected urine into their eyes or by eating hay or feed contaminated by infected urine.

Once infected, horses might experience fever, become listless, or go off their feed. Their eyes can become painful, causing swelling, squinting, blinking, cloudiness, and tearing. Pregnant mares will often lose their foals late in gestation. Adult horses might show signs of jaundice (yellowing of the mucous membranes or eyes) in the latter stages of the disease and can die of liver and/or kidney failure. If you see any of these signs in your horse, consult with your veterinarian.

Equine leptospirosis prevention involves good management to keep wildlife out of areas where horses live and eat. Horses should not be allowed to drink from stagnant water or ponds that might be contaminated with cattle urine. Owners should disinfect areas where known infected animals have been before introducing new animals.

Leptospirosis is a zoonotic disease--one that can be transmitted from animals to humans. Veterinarians and owners should use care when handling a suspect animal so as to not be exposed. They also should use protective gloves and glasses when working with the animals that have aborted. Be sure to wash any exposed body parts thoroughly with antibacterial soap. Remove contaminated bedding and spray stall areas with a disinfectant. A video on stall disinfection by Roberta Dwyer, DVM, MS, Dipl. ACVPM, a professor in UK's Department of Veterinary Science is available.

Many veterinarians are treating mares suspected to be infected prophylactically (i.e., prior to seeing clinical signs or abortion). The drugs of choice for infected horses are oxytetracycline, streptomycin, or penicillin. Vaccines are available for dogs and cattle, but not for horses. The cattle vaccine has been used in horses with poor results and often with side effects.

The UKVDL can assist veterinarians in diagnosing leptospirosis by testing blood and urine for evidence of the disease. In addition, owners/veterinarians should submit aborted or weak foals that die to the laboratory for a complete necropsy and testing for the disease.

Furthermore, the UKVDL is conducting a national sero-epidemiological study of equine leptospirosis to better understand the distribution of horse exposure to leptospires and to lend strength to the idea of a vaccine for the horse. Study results will be published this year and presented at the Equine Diagnostic and Research Seminar at the UKVDL on Aug. 30.

Visit the UKVDL website for the latest statistics on leptospirosis, herpes, and nocardioform placentitis-related abortions.

For more information contact Craig Carter, DVM, PhD, Dipl. ACVPM, director of the UKVDL and professor of epidemiology, at 859/257-8283 or Craig.Carter@uky.edu; or Jacqueline Smith, epidemiology section chief at the UKVDL, Jacqueline.Smith2@uky.edu or 859/257-8283.

Craig Carter, DVM, PhD, Dipl. ACVPM, director of the UKVDL and professor of epidemiology, provided this information.

Want more articles like this? Sign up for the Bluegrass Equine Digest e-Newsletter.

More information on Gluck Equine Research Center and UK Ag Equine Programs.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from TheHorse.com. Learn More