Our clients have to fill out an application including information about pets, financial information, etc. We also require that each client allow a home visit at least once per year. (When we added the home visit we had a SUDDEN drop in the number of interested people. I wonder what they did not want us to see?) We have a monthly distribution day and we have purchased sturdy food grade buckets with reusable lids that the food is distributed in. We have a few clients that actually get home delivery (due to medical reasons that make coming to pickup to difficult for them) We do not have an absolute s/n requirement but we definitely point people in that direction, and help them find funding for it. (We have a few clients who have tiny little house dogs that are literally never outside not on a walking leash or use pee pads indoors. They are NOT reproducing.) In 4 years of this program only once have we had to intervene because a litter of pups was born.
Our program focuses on forming close friendships with our clients. It is more than just a pet food pantry. But even when it was "just" a pet food distribution service, using the buckets to control how much each client received and have only a monthly distribution point kept things manageable.