Our neighbor has a mature male Rott who growls at my husband. This neighbor babysits for our 2 and 3 year old children and lets the Rott run loose. What should I do?

I REALLY need some advice. Our babysitter and neighbor whom we dearly love is the owner of a Rott by the name of "Baby." The dog is actually her husband's pet & has been fairly well behaved around me and my children so far, they have lived beside us for approximately 1.5 years. However, the dog has shown some aggressive territorial behavior to my husband. For instance when he was putting mail in our box which border's their yard, he has growled, or has come up in the drive when Lambert was getting in his truck.

When our neighbor first started to baby-sit for us, the dog was always kept in the kennel while the children were outside. I've been finding the dog loose in the yard when I pick up the children. This is a very big dog and my children are ages 2 & 3. So this dog is face to face with my little boy, whom he has licked in the face. No harm there yet, but I've heard so many stories in regard to these types of dogs, I want to know your opinion of this situation. Is this an accident waiting to happen? One of my concerns has been the territorial aspect of this breed, our sitter also has 2 children, if all 4 children are at play in the yard and one child gets hurt, would this dog assume that their child needed to be protected from the other children? Is this something I should be concerned about?

We have already said something to our neighbor, asking them to please keep the dog locked up when the children are playing in the yard, but I'm not sure they didn't take offense. I don't like to hurt anyone's feelings or cause hardships over pets, but I'm a 100% committed to protecting her children parent.

Any thoughts and advice you can give me would be appreciated.

Sheila