Just last month the Centers for Disease Control and Prevention declared victory over canine rabies in the United States -- a fatal virus that kills 55,000 people a year globally.

That declaration may have been premature.

A growing demand for overseas dogs -- many from countries where the disease is endemic and the animals are too young to be vaccinated -- has put rabies back on the government's radar and caused the CDC to go to work on stricter rules aimed at imported dogs.

As many as 300,000 puppies a year are being imported, based on early estimates, according to G. Gale Galland, veternarian in the CDC's Division of Global Migration and Quarentine.

Driving the import trend is the demand for puppies, rather than older dogs that have behavioral or health issues.

The Border Puppy Task Force in California estimates that 10,000 puppies entered San Diego County from Mexico in just one year. Some only a few weeks old are sold for $1,000 each in shopping center parking lots on the street.