Case Report - Johne’s Disease

The Recipient Risk

Abstract

This is the first report of intrauterine Mycobacterium paratuberculosis transmission from a bovine embryo recipient to the resultant calf. The recipient was ELISA and fecal culture test-negative before embryo placement, but became ELISA-positive during the pregnancy. Johne’s disease was confirmed at necropsy subsequent to Caesarean section. Her embryo transfer calf was diagnosed with Johne’s disease two years later. Strict research biosecurity protocols under which the embryo transfer calf was raised eliminated routes of post-natal exposure to M. paratuberculosis. The recipient cow had been purchased from a herd at risk for M. paratuberculosis infection for which no Johne’s disease surveillance was performed.
To minimize the likelihood of purchasing an infected recipient cow or obtaining M. paratuberculosis- contaminated colostrum and thus jeopardizing valuable embryos, recipient and colostrum donor purchases should be made from a source herd with no or low, whole- herd Johne’s disease test prevalence. The risk of purchasing an animal with M. paratuberculosis infection can be better assessed with whole-herd infection prevalence data than with test results for a single animal only.