I was able recently to get dog food from Publix very cheap and plan on donating it all to the local humane society. I know a lot of the animal shelters are desperate for supplies right now, so if you can save enough to be able to donate it is greatly appreciated.
Publix had a certain dog food for 2 for $5 (or $2.50 per bag) and I had coupons that took $2 off per bag making them only $.50 a bag. I had enough coupons to get 10 bags to donate and only spent $5 out of pocket. I try to keep an eye out for great deals on pet food to be able to continue donating to the animals as much as I can.