Expert on paratuberculosis, also called Johne's disease, in animals.
- Mycobacterium paratuberculosis as a potential human pathogen and food safety concerns.
- Johne's disease: diagnosis, control and epidemiology.
- University of Minnesota, College of Veterinary Med., Distinguished Research Alumnus Award, September, 2010.
- UW-Madison School of Veterinary Medicine, Norden-Pfizer Teaching Award, May 2004.
- UW-Madison, Van Hise Distinguished Teaching & Outreach Award, May 2004.
- Fulbright Scholars Program Award: support for sabbatical in Chile 2004-2005.
- Past president, International Association for Paratuberculosis