The use of oral fluid diagnostics in swine medicine

Swine veterinarians in North America have applied oral fluid-based testing methodologies for an increasing number of systemic, respiratory, and enteric disease diagnostic applications. Since the first report of oral fluid testing in 2008, nucleic acid and antibody assays have been described in the peer-reviewed literature for many pathogens affecting swine. As evidence of the US swine industry's growing utility of oral fluids as a diagnostic tool, the cumulative number of swine oral fluid diagnostic tests conducted at three veterinary diagnostic laboratories in the upper Midwest (Iowa State University, South Dakota State University, and University of Minnesota) has increased from approximately 21, 000 tests in 2010 to nearly 370, 000 tests in 2016. The objective of this review is to describe the developments in oral fluid diagnostics that have led to its widespread use and to highlight areas of concern as this technology is increasingly implemented by producers and veterinarians.