Please help! Young barn kitten has been mauled by a dog!?

We found a young kitten (just been weaned off milk for a few days) and he was layed out in the gr where the dog had left him. He has no cuts or external wounds. He could possibly have internal injuries? His eyes are open and he will drink some water from a bottle but not much. His legs twitch and he won't move. I have him lying on a soft bed in a tub with a thin sheet over him. Is there anything more I can do (parents won't pay for a vet bec. "its a barn cat and we have too many anyways!" ) Please help.