From the American Veterinary Medical Association:
It was recently brought to our attention that there are rumors circulating online about the existence of two new strains of canine distemper virus. These rumors are untrue. After consulting with two experts, Dr. Ed Dubovi (from Cornell) and Dr. Ron Schultz (from the University of Wisconsin), we provide the following information:

  • There is no data to back up claims that the disease is on the rise on a national level, but there have been many outbreaks of distemper covered in the news media.
  • Genetic studies of the canine distemper viruses in the U.S. may show strains that were previously undetected here, but it’s almost impossible to determine if these strains are newly arrived or just newly detected because of improvements in testing. In addition, minor genetic changes often do not affect the antigenicity of the virus and have no impact on the efficacy of currently available vaccines.
  • The currently available distemper vaccines are highly effective and will protect dogs against all currently circulating strains of canine distemper virus.
  • The real issue is that there are unvaccinated (or inadequately vaccinated) and unprotected pets at high risk of developing a very deadly, yet preventable, disease.
  • Dog owners are strongly urged to consult with their veterinarians regarding vaccination of their dog against distemper and other common diseases, including adenovirus, parvovirus and rabies.