Other animal rights groups say adopting overseas makes no sense when 4 million unwanted dogs are put to death each year.
"We are obviously barely coping with our own overpopulation crisis," said Daphna Nachminovitch, director of People for the Ethical Treatment of Animals (PETA), who said many animal shelters face little regulation, and budgets for animal control are strained.
"If a shelter is empty, it's not doing its job," said Nachminovitch. "I can take you anywhere in this country and on streets are homeless, unsprayed animals with litters. I talk to people in the trenches every day. Their doors are not wide open enough."
Even though dog overpopulation is rampant in some states, particularly in the South, successful spaying and neutering programs in the Northwest, California and the Northeast have created a dearth of adoptable puppies, say local shelters.
One rescue group -- Save a Sato (Spanish slang for mixed breed) -- has brought an estimated 14,000 dogs from Puerto Rico to the United States since its founding in 1996, according to Massachusetts volunteer Twig Mowatt.
The island is home to thousands of abandoned and abused dogs in need of homes.
"It's a beautiful thing," said Mowatt, who herself adopted a terrier named Rico. "People are really desperate for an adoptable dog, and they don't want to go to pet stores or breeders. Otherwise there would be nothing."
In Massachusetts, where many of these dogs are adopted by shelters, puppies must be held for 48 hours before being released to homes to watch for signs of illness.
But protocol failed in 2004, when one puppy was diagnosed with rabies during quarantine at a shelter in Cape Ann, Mass. The puppy -- only several months old -- developed neurological problems consistent with rabies and was euthanized, according to Donna Rheaume, a spokesman for the state department of health.
A state lab confirmed the animal had rabies, she said, and all who had handled the dog were given preventive treatment.
Shelter Inc. of Sterling, Mass., accepts two or three Puerto Rican dogs a month for adoption. The shelter also takes local animal control surrenders and seeks out dogs who need homes from states like Tennessee and Virginia.
"We have much higher protocols than picking them off the street and throwing them on a plane," said director Leigh Grady, who even took in a puppy from Thailand after the 2004 tsunami.
"That dog had books of medical history," she said. "He had a better medical passport that I did."
The shelter charges $350 for puppies, a fee that covers the costs associated with transportation and medical care. The shelter also carefully screens its adoptive families.
"Everyone wants to help, especially if they can save an animal that was abused," said Grady. "They went the breeder and pet store route and they want to do the right thing."
Meanwhile, the CDC said it is not opposed to importing animals, rather it hopes stricter regulations -- now in review and expected to take effect next year -- will continue to do what it has hailed as one of the greatest public health successes of the last half century -- eliminating canine rabies.
"If animals are being imported responsibly, that's OK with us," said Marano.
Still, she said, about working with shelters and rescue operations, "Let the buyer beware."
"It is safe in the U.S. because we work very hard to keep rabies out," said Marano, a practicing veterinarian. "But you always have to be careful. Pick the brightest puppy in the bunch and not the runt -- the one that looks healthy and has a good disposition, and some sort of health certificate from the pound."
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