It would depend on the dog, and his parents...there are many "bull dog" types out there...often people mix up the individual breeds and just mash them together as bull dog/bull terrier, so viewing the dog and its parents if possible would be the best option. Or just make sure dogs are kept separate to kids.

Lulu I'm sure that mix isn't quite as bad as a kelpie x cavalier...although the resulting puppy was quite cute! Has cavvy ears with slightly crimped fur, and a cavvy looking face but long legs of a kelpie! Definitely an *oops* litter... and then there was the litter of pups my brothers dog had, which were kelpie x sausage dog (sausage dog was the dad...imagine that..he sure wasn't going to give up lol.)