I briefly touched upon this in my dog nerd post a while back where I also linked to my puppy mill rant from several years ago. But it doesn't hurt to touch upon the issue again.
I don't care what kind of pet store it is, if they sell puppies or kittens, I stay away from it. Majority of time the puppies are going to be from a puppy mill. There are TONS of links on what a puppy mill is, stoppuppymills.org being my main go to site for information. However if you have no idea what one is, its essentially a place where people over-breed dogs for profit. And I'm not talking about a handful of damas that are giving birth, these are rows and rows and rows of dogs crammed into cages, constantly breeding. The conditions are filthy and the dogs are all unhealthy.
Petland is the most well known pet store chain that sells puppies. And the biggest store that activists have been trying to bring down. The employees are told that the puppies are from local breeders, but its all lies. The paperwork has names of companies that the puppies come from that are known brokers for puppy mills. Animal Planet actually did a special awhile back ON Petland, where it followed an undercover investigator going to known puppy mills, trying to get video footage to help in a case where owners of Petland puppies are trying to sue Petland for selling dogs from these places.
Even if some of these pet stores DO get puppies from local breeders, I still wouldn't touch these dogs with a 10 foot pole. Any RESPONSIBLE breeder is going to want to screen and choose a home for their puppies ON THEIR OWN, and not leave it up to a pet store's discretion. Even Petco and Petland who house cats that are up for adoption can't adopt out the cats without the adoption rep approving of the adopter's application first. The fact that there's ma and pop type shops that are selling dogs and cats, and trying to make it seem okay that they're from local breeders, upsets me.
If its too much work for you to research and find a responsible breeder for your new addition to the family, you PROBABLY SHOULD NOT BE GETTING A DOG!!!! Dogs are a LOT of work, a HELL of a lot more work than the "inconvenience" of researching and finding the right dog for your home.
So, visit your local shelters, take time to research and find the right dog. I'm a huge adopt over buy advocate, however if you are dead set on a specific breed, and are unable to find the right one through rescues, find a responsible breeder. Someone who health tests their dogs and is active in the dog community (I prefer dog sports over dog shows personally). And for crying out loud VISIT the home of the breeder, ASK to see the mother and/or father of the litter you're looking at. If the mother/father is shy, fearful, aggressive, anything that sets alarm bells off in your head, DO NOT BUY THEIR PUPPIES. You want a mother and father that have a good temperament and look healthy.
I leave you with that to chew on and some old old posters I designed a few years ago on puppy mills :P
Day 01 → Your favorite song
Day 02 → Your favorite movie
Day 03 → Your favorite television program
Day 04 → Your favorite book
Day 05 → Your favorite quote
Day 06 → Whatever tickles your fancy
Day 07 → A photo that makes you happy
Day 08 → A photo that makes you angry/sad
Day 09 → A photo you took
Day 10 → A photo of you taken over ten years ago
Day 11 → A photo of you taken recently
Day 12 → Whatever tickles your fancy
Day 13 → A fictional book
Day 14 → A non-fictional book
Day 15 → A fanfic
Day 16 → A song that makes you cry (or nearly)
Day 17 → An art piece (painting, drawing, sculpture, etc.)
Day 18 → Whatever tickles your fancy (Dog Nerdism)
Day 19 → A talent of yours
Day 20 → A hobby of yours
Day 21 → A recipe
Day 22 → A website
Day 23 → A YouTube video
Day 24 → Whatever tickles your fancy
Day 25 → Your day, in great detail
Day 26 → Your week, in great detail
Day 27 → This month, in great detail
Day 28 → This year, in great detail
Day 29 → Hopes, dreams and plans for the next 365 days
Day 30 → Whatever tickles your fancy