Unfortuantely it's your responsibilty to keep them apart, including crating or using baby gates or whatever means necessary to prevent your toddler from grabbing the dog so he doesn't get hurt. It's not fair to her to have to be grabbed either, she doesn't understnad it and it probably hurts. Use crates or baby gates to keep them separated, and a playpen is also probably a good idea if you cant directly watch him or them. That's really the only solution. You can take the gates down when hes napping or in bed and let her have free roaming again but you dont want your baby to be harmed or the dog to have to be removed.