i know that at usps they have a petsmart coupon in their "moving guide" for $5 off a $10 purchase.
i'm looking online for codes but many of them require a $50 or $75 purchase for $10 off..something like that.
i found one, but i don't know if it works. here you go. it's $5 off $10 purchase online.
http://www.californiafreebies.com/petsmart-coupon.htm
i'll keep looking for you!