A diagnosis of distemper in our canine patients is often made more difficult by the inability of molecular diagnostic tests to differentiate infection from vaccination. Recent research compared the viral load of infected vs. vaccinated dogs using real-time PCR.1 Respiratory mucosal swabs were obtained within the first three weeks of vaccination in healthy dogs as well as from acutely infected dogs. Viral loads were measured, and cutoff values were established to help differentiate between the two populations. Acutely infected dogs were found to have viral loads significantly higher than the cutoff values for vaccinated dogs, indicating quantitative real-time PCR may help discriminate vaccine vs. infection in the clinical setting.
This "Presentation Recap" summary from the 2011 American College of Veterinary Internal Medicine (ACVIM) Forum, which took place in Denver, Colo., was contributed by Jennifer L. Garcia, DVM, DACVIM, a veterinary internal medicine consultant in Houston, Texas.
1. Leutenegger CM, Crawford C, Levy J, et al. Canine distemper virus quantification by real-time PCR allows to differentiate vaccine virus interference and wild-type infection (session abst). J Vet Intern Med 2011;25(3):754.