Once they are fully weaned (approximately 8-10 weeks), you should gradually work up from a soft gruel to a high quality dry dog kibble as the main staple. To this, you can add whatever meals, snacks and treats you wish. What one raccoons loves another may turn his nose up at.
Carrot lovers are rare. Most will devour uncooked corn on the cob (and have a ball shucking it themselves) but this is not advisable if you will be releasing them in an area near corn farms. Same goes for watermelons.
All my raccoons loved dog biscuits and grapes and they can be very useful as bribes.
Raccoons have a sweet-tooth, and will do anything for a marshmallow. It is not advised to give your coons sweets. Use any sweets sparingly.
I buy minnows and crickets at the bait shop and the raccoons enjoy fishing and hunting for them. I also pick up mice and cray fish for them. This teaches them invaluable skills they will need in the wild. They also enjoy digging for grubs and other tidbits and the nuts and berries.
Basically, a raccoon will put ANYTHING it finds into its mouth. If it tastes good to him, he eats it.
