Petco has Science Diet 40lbs bags for 34.99. Use the 5.00 off coupon to get 40lbs of food for $30.00
If you have got your ProPlan coupon you could combine it with their $5.00 off sale on 35lb bags.
Petsmart has a 15% off your in store purchase coupon available here. Move quickly it does expire today.
Target has various dog and cat items for 9.99. Check your local ad. I didn't see anything spectacular listed.