Make sure the tic's head is removed from the dog's body and it should all be OK. If the head is still there, then pinch it between two fingernails and pull out. If a full bodied tic is there, make sure the head comes away with it, put in ashtray and set light to body and it will go pouff as they are notoriously difficult to kill.
If you rub the tick with metholayted (?) spirit this should make it easier to remove. i use tweeezers.
As netibiza says it is important to remove the head. the meths helps.