Leptospiral abortion and leptospiruria in horses from the same farm.

The research study investigates an occurrence of abortion in a mare caused by Leptospirosis. It focuses on how tests detected this disease across multiple horses in the same farm, studying the occurrence and spread of the bacteria in these animals.

Leptospirosis causing Abortion

• The researchers found that the direct cause of an abortion in a mare was Leptospirosis. This bacterial disease was detected via a histologic evaluation of silver-stained sections from the fetal kidneys and placenta.
• Leptospirosis usually affects animals and can cause various symptoms, including abortion in severe cases. This discovery reiterates the harmful effects of this disease on horses.

Identification of the Specific Leptospira Strain

• The microscopic agglutination test used indicated that the Leptospira interrogans serovar pomona was present in fetal serum at a titer of 1,600.
• The mother mare had serum titers with varying levels to different Leptospira interrogans serovars which were bratislava, canicola, grippotyphosa, hardjo, icterohaemorrhagiae, and pomona.

Serologic Survey and Spread Across the Farm

• A serologic survey was conducted on the farm. This survey revealed high titer levels of at least 6,400 against serovars bratislava and pomona in 5 other horses in the same farm.
• Moreover, there was a significant percentage of horses (53%) which showed titers of at least 100 against the serovar bratislava. This indicates a widespread presence of the bacteria on the farm.

Detection of Leptospires in Urine Samples

• Direct fluorescent-antibody tests were conducted to further confirm the presence of Leptospires. These tests were performed on urine samples from various horses.
• Results showed that Leptospires were present in the urine samples from the mare that had aborted, as well as from two of the five other horses that showed high titer levels. This suggests not only a widespread presence, but also a potential means of transmission through urine.