Leptospirosis: An important infectious disease in North American horses.

The research article explores leptospirosis, a common infectious disease in North American horses caused by Leptospira organisms. The main consequences of this disease are related to the placenta and fetus, kidneys, and eyes in horses.

Leptospira Serovars Involved

• The paper elaborates that Leptospira Bratislava is the most frequent serovar found in horses, but it has not been confirmed to trigger clinical disease in North American horses.
• Leptospira Pomona type kennewicki is identified as the primary cause of clinical diseases, such as leptospirosis, in North American horses.

Common Symptoms and Diseases

• The diseases linked to leptospirosis most often affect the placenta and the fetus, the kidneys, and the eyes in horses.
• In-utero infections can lead to abortion, illness in newborn horses, or the birth of a healthy, antibody-positive foal.
• Acute renal failure in younger horses and recurrent uveitis in adult horses are two highly documented clinical symptoms of leptospirosis.
• Abortions, newborn disease, and acute renal failure are often the result of a subacute Leptospira infection, while recurrent uveitis can occur months or years following the initial infection.

Diagnosis and Treatment

• Leptospirosis is diagnosed through a combination of antigen or antibody testing methods.
• Mares that have abortions after a Leptospira infection may not exhibit additional clinical signs at the time of abortion but may excrete the Leptospira bacteria in their urine for several weeks.
• In some cases, antibiotics are administered to reduce Leptospira shedding in infected horses or as a preventive measure in exposed pregnant mares, although the effectiveness of this measure is not well documented.
• Successful treatment of horses with Leptospira-associated acute renal failure involves the use of antibiotics and supportive care.
• Despite systemic antimicrobial therapy, horses with chronic intraocular infection triggering an immune disease, known as recurrent uveitis, commonly associated with leptospirosis are not able to completely eliminate the organism from the eye.

Vaccination

• A vaccine for Leptospira Pomona type kennewicki, approved for use in horses, is now available in North America, offering a preventive measure against leptospirosis in horses.