Great ideas so far!
Is your charity tax deductible? make sure you mention that - and post that as well.
can you get donations? Say... a free dog obedience course offered by a local trainer.. someone to donate this and you can raffle it off? Spay/Neutor? a free vet visit, vacination shots, kennel (for when owners need to go out of town).. get donations like that.. Make posters to showcase the prizes..
food.. never a good idea! that is creepy to me (i never buy that stuff as I am paranoid).
I love the idea of the donations.. "We need xyz, please think of us while your shopping" type of thing. Give them a neon colored note card of what you need..
![Smile](https://pics3.city-data.com/forum/images/smilies/smile.gif)
.. keeps it in their mind as they are shopping and as they are checking out.
For the future...
Hold a contest in your area with "local cats having fun" and do calendars, note cards, etc... to sell in the future.
good luck