I’ve written a lot lately about importation of pets and associated infectious disease issues. A recent paper in the journal Zoonoses and Public Health (Sinclair et al, Dogs entering the United States from rabies-endemic countries, 2011-2012) provides some interesting data on this topic.

Dogs entering the US from countries where rabies is present must be vaccinated against this disease. If they are not vaccinated, the importer must sign an agreement that says the dog will be confined until it is fully vaccinated, i.e. 30 days after it receives its first vaccine. Dogs have to be at least 3 months old to be vaccinated, so any dog under that age must be confined until it is 3 months old, vaccinated, and then confined for an additional 30 days post-vaccine.

The study focused on dogs that had to be confined due to lack of rabies vaccination on entry to the US.

  • Over a 1 yr period, 2746 dogs were confined. That’s a pretty impressive number of imported dogs considering this only accounts for unvaccinated dogs from countries where rabies is present.
  • Dogs originated from 81 different countries. Canada (21%), Mexico (13%) and Europe (30%) were the most common sources. Dogs from Mexico would be the greatest concern of these because of the presence of canine rabies in that country. Europe is variable risk, with rabies in wildlife and dogs imported from higher risk regions. It’s not clear to me whether some of these "European" dogs might have actually originated elsewhere and been funneled through Europe, which would make them higher risk as well.
  • 11.4% of the dogs came from South America, 8.5% from Asia and 1.2% from Africa. These are all higher risk regions.
  • Most (67%) were puppies less than 3 months of age (so too young to have been vaccinated.)
  • The nature of the movement of the dogs (e.g. how they arrived, where they arrived, from where they came) in comparison to human travel patterns led the authors to conclude that most were "entering the United States for increasing the dog supply", as opposed to people traveling with their own pets. 

One of their other conclusions was “Dogs unimmunized against rabies and coming from rabies- endemic countries (i.e. DPCAs) continue to be imported into the United States in considerable numbers. These DPCAs pose a demonstrated risk for re-introduction of canine rabies virus variant and may also pose risks for entry of other animal and zoonotic diseases.

If over 2700 unvaccinated dogs were brought into the country, how many dogs were brought in in total? How many of the "vaccinated" dogs were really vaccinated? (Since scrutiny is limited and faking a vaccine certificate doesn’t exactly take a lot of effort.) What other pathogens might those thousands of imported dogs been carrying? Finally, why import those dogs in the first place? There’s hardly a shortage of dogs looking for homes in the US…