Mycobacterium avium subspecies paratuberculosis (MAP) causes Johne’s disease, a chronic infectious disease of ruminants. Infection normally occurs in the neonatal period when calves ingest an infectious dose of MAP. The clinical, irreversible and ultimately fatal disease does not occur until years later. In the meantime, animals with preclinical Johne’s disease may look healthy while still shedding MAP in their feces, transmitting the disease to new animals.
There are no effective vaccines or treatments, and diagnostic tests fail to identify many infected animals in the pre-clinical state. Research currently underway and funded by the National Check-off and Canada’s Beef Science Cluster is working to Continue reading