The animal health company Zoetis has a new vaccine available for horses that need protection from leptospirosis. Because this is a disease that hasn't had a vaccine available before, many horse owners don't know their risks. Therefore Zoetis has created a short quiz you can take to see if your horses might be at risk and determine if you need to discuss leptospirosis risk with your veterinarian.
Research has shown that 75% of 5,261 healthy horses tested positive for at least one leptospiral serovar in a study involving 53 veterinary clinics in 18 states. Horses are primarily affected by Leptospira interrogans serovar Pomona, or L.pomona, in North America.3 Although classified together, serovars are distinct variations within a species of bacteria. L.pomona is the leptospiral serovar most commonly associated with clinical disease in horses.
Horses can become infected when exposed to bacteria in urine from:
- Contaminated soil, bedding, feed and drinking water
- Standing or slow-moving water
- Maintenance hosts such as skunks, white-tailed deer, raccoons and opossum
Genetics may play a role, as well. Appaloosas, Drafts and Warmblood breeds are more frequently and severely affected by Leptospira-associated uveitis than other breeds.7,8
Additionally, outbreaks of leptospirosis may be related to rainfall. Heavy rainfall can increase the risk of leptospiral abortions by as much as 3.7 times, with losses as high as $4.2 million for the Thoroughbred breed alone.
Clinical signs associated with acute infection are general, such as fever, depression, anorexia and pain.
Diagnostic testing can be challenging as the most commonly used diagnostic test is the Microscopic Agglutination Titer (MAT) test; however, a single titer does not differentiate between exposure and infection. Multiple titers taken at different times may be helpful in diagnosing disease, as well as other sophisticated tests.
To learn if your horses are at risk, take this short quiz, then talk to your veterinarian.