Bovine abortion caused by leptospirosis

A 3‐year‐old, 255 kg, mixed breed beef cow has an abortion at the last trimester of gestation, approximately 8 months. The cow was from a 1200‐hectare farm, with 1200 animals. The farm owner reported a total of 13 abortions between June and September 2022, all of them in the last trimester of gestation. Additional serological screening for Leptospira was performed in 40 cows from the herd by microscopic agglutination test with seropositive animals to serovars Icterohaemorrhagiae. Gross postmortem examination yielded icterus, pleural and peritoneal effusions. Histopathological findings were lymphoplasmacytic interstitial pneumonia and nephritis, with intraluminal spirochetes within the renal tubules, hepatic necrosis, and cholestasis. PCR on a fresh tissue pool was positive for Leptospira spp. (LipL32). Leptospirosis is a zoonotic disease, caused by the infection of the bacterial spirochetes belonging to the genus Leptospira spp. Serovars Pomona and Icterohaemorrhagiae cause acute systemic leptospirosis in cattle after incidental infections due to poor husbandry conditions and cause abortion loss in cattle in occasional outbreaks.