Omaha, Neb. Type "Yorkies for sale" into an Internet search engine, and hundreds of Web sites come up.
Animal welfare advocates say the Internet has become the latest vehicle for large-scale dog breeding operations - or "puppy mills" - to sell their wares.
The concern is that people who sell dogs over the Internet are able to skirt federal licensing and inspections because they are not considered wholesalers. And because most states don't have puppy lemon laws, an Internet buyer often has no recourse if his or her new dog has health problems.
"People are getting suckered," said veterinarian Helen Hamilton of Fremont, Calif.
Hamilton said some of her clients have been victimized by Internet dog sales. Many of the puppies are diseased because of dismal kennel conditions, or have genetic defects because of inbreeding and other poor breeding practices, she said.
Stephanie Shain, outreach director for the Humane Society of the United States, said buyers should do more than view photos provided by the breeder.
"You have to absolutely go and see the operation," she said. "It's sad but true. You can't trust the pictures they send you in an e-mail. You need to see the conditions the puppies are born into."
Animal welfare advocates encourage buyers to meet the parents of their prospective puppy. That not only allows the buyer to see the breeders' kennel conditions, but it also gives an indication of the puppy's temperament.