North American Veterinary Licensing Examination (NAVLE) Practice Test

The most appropriate management plan for a herd suspected of having Johne's disease is to test the herd, treat positive animals, and remove calves from their dams at birth. This approach is critical in managing Johne's disease, which is caused by Mycobacterium avium subspecies paratuberculosis (MAP).

Testing the herd allows for the identification of infected individuals, which is essential because Johne's disease is often subclinical in early stages and can spread within the herd. Once positive animals are identified, appropriate management strategies can be implemented, including possible treatment options though it’s worth noting that treatment in severe cases may have limited efficacy.

Removing calves from their dams at birth is particularly important because MAP is primarily transmitted from infected dams to their offspring through colostrum and milk. By preventing the newborns from consuming milk and colostrum from infected dams, the risk of transmission is significantly reduced, thereby helping to control and contain the spread of the disease within the herd.

This comprehensive strategy emphasizes both detection and prevention, which are crucial for effective management of Johne's disease, ultimately improving the health of the herd over time. It works to mitigate further spread and supports the long-term nutritional and health needs of future generations of animals.