I have found that both Big Name "Pet" retailers in the US to be very, very, touch and go both on cleanliness and knowledge. I often purchase supplies for my pugs and our snakes at them, however I would never buy anything live from them, other than fruit flies. Here in Omaha, PetSmart is better stocked, but PetCo has better prices.

If I were to make a judgment call on employee knowledge between the two here, PetCo would win, however I found that most of them in other locations around the country were masters of misinformation.

Then again, I am a bit of an elitist when it comes to pet shops in general...