8. Pet Store Dangers
Dogs have been bred for hundreds of years, and today, the American Kennel Club recognizes over 150 breeds. With so much breeding going on, genetic problems caused by inbreeding are inevitable. "There are all kinds of problems from inbreeding," says Colvin. "People are almost trying to get clones. If someone doesn't know what they're doing from a breeding standpoint, it can accentuate negative traits like aggression, congenital problems, and physical problems."
Breeders of all types face these challenges, but responsible breeders take special precautions to prevent their dogs from carrying on genetic defects. For example, many good breeders limit the number of litters their animals have to one or maybe two each year.
When you buy a pet from a pet store, you have no way of knowing whether your animal will be healthy or not, because you don't know the breeder. Further, to bolster profits, pet stores notoriously buy their animals from so-called "puppy mills" who focus on sheer numbers, not on the health and welfare of their animals.
But the mixed breed dogs you'll find at a shelter are less likely to carry the problems of heredity, simply because they've come from a larger and more diverse gene pool. According to Buchwald, scientific studies have shown that cross-breeds are heartier than purebreds. "With every breed, there is some genetic disorder that is associated with the gene pool in that breed," she says.
If you do decide to go to a breeder, do plenty of research to find a breeder who is reputable and responsible, so you can make sure your new pet is healthy and happy.