It could have been a garter (not gardener) snake -- check here for some great pictures so you can be more sure.
If it is, garter snakes do have venom but it's very mild and non-toxic. Also, they have small teeth that rarely break the skin. Unless you have an unusually large garter snake, your animals are probably fine. (But I'd be careful if you have baby rabbits that a snake could get at -- newborn bunnies are pretty tiny.)