Don't buy dogs online: shopping via the internet is quick and convenient. But is this a smart way to choose an animal companion? Experts weigh in.

How much is that doggie in the window? In this day and age when almost everything we use or want can be had online, the window we're talking about here is not a window in a pet shop but the screen on your computer. The American Pet Product Manufacturers Association estimates that 150,000 to 200,000 puppies were bought online last year by American families.

Convenience is the main reason people search online for the perfect puppy. It's a fun and easy way to see many different kinds of puppies and dogs at once. But buyer beware: Many canines have arrived sick, chronically ill or injured during transit. Often, the good-tempered dog you were promised turns out to be anything but the dog …