I wouldn't comment on the Petco situation, because I wasn't there and I don't have any of the facts. That being said, I usually DO NOT use the services of large chain pet and pet supply companies. Neither do I deal with puppy mills or super breeders.
I get my pets either through rescue centers and/or selective owners whoe family members (dogs, cats, birds , horses, ect.) are occassionally bred as part of their pets normal life cycles.
To many unknowns when you can't observe the breeding conditions, and the conditions of their breeding pets.
Missy, our Yorkie , was rescued from a house with 135 dogs at one time. We are lucky to have her as part of our family.
Paco, our Chorkie, (Chihuahua/Yorkie cross) was a rescue from a home with eight small dogs, all kept in small carriers and used for breeding designer dogs. He is one little ball of love and has been a blessing since coming to us.
Neither would we have purchased from those who had them, but, we were glad to get them out of the situation.
Kittles, our Blue Front Amazon, was purchased by my son12 or 13 years ago and we were able to take charge of him when my son got a job that keeps him on the road.
Some day he may go back to him. Until then, he's my little buddy and will remain as part of our family as long as he can.
I believe pet owners, in general, could do great things in the area of pet care and pet abuse by simply NOT giving in to the urge to by some fru-fru dog stuck in a petstore wire cage.
Semper Fi!
Forbey