Hello. Please forgive my ignorance and probably media-driven fear of the beautiful and loving Pit Bull breed. I have seen what wonderful, loyal, beautiful dogs these can be WHEN THEY ARE RAISED PROPERLY AND TRAINED, given attention, taken on long walks, and lavished with attention and praise. I am sure that dogs raised properly of this (or nearly any) breed are normally wonderful pets, and loving companions.
However, I am facing a somewhat difficult situation here. My brother in law is, to say the least, NOT a responsible pet owner. He is not even a responsible father. He is the type of guy to put his kid in a messy room with a tv on the floor on his only weekend of the month visitation and tell him to leave him alone so he can watch football in the other room, so you can imagine how much attention he would lavish on a dog. Well, about a year and a half ago he got a (supposedly "purebred", no papers that I am aware of) Pit Bull puppy. Her name is Sacha. Beautiful dog. It was, in my eyes, a disaster waiting to happen. He is rarely home, he drinks a lot, he goes out a lot, his home is a disaster, and he does not keep things sanitary. The dog was to be crate trained. This meant she spent approximately 10-12 hours a day (if not more) in her crate, one that was far too small for her (not like, illegal small, just immorally small), and obviously for far too much time each day. We live in Michigan, the winters are brutally cold. When she was not in her crate, she was outside, no doghouse. Not so much that she froze, and not with anyone to play with. Just alone, so that she did not bother anyone. When she was inside and not crated, she was yelled at, and both my brother in law and his son (now 7 years old), yank on her collar when she jumps on the couch or whatever and yell at her, "get down, Sascha", etc (not in a Cesar tone, more like a disdain tone, disgust or talking down to the poor dog, who just wants some attention and love). So this is a Pit Bull, probably NOT purebred, but possibly, who has been neglected for attention, and stuck in a crate far too much, and gets almost NO interaction or excercize at all. She chewed through her crate. He locked her in the bathroom. She ate a bunch of towels and almost died, he was going to let her, because he could not afford to care for her. His girlfriend paid for her operation. He was evicted, and he has been passing her around to anyone who will take her since then, and now comes MY biggest problem (besides that I hate that the dog has been treated like crap by him for so long).

My Mother In Law and Father In Law have taken the dog in. They say temporarily, but I don't buy it. Frankly, I am sure they would give the dog the best possible life that she could ever have anyway, given the circumstances. They have 2 other dogs, and 3 cats. One is a chow mix, and the other a small (and very unintelligent, weighs under 10 lbs) rat terrier mix.
But I have a 3 1/2 old son who has been nipped by the rat terrier mix, and he has also has a scare with a vicious dog that lived behind us and tried to hop our fence and attack us (I got him away just in time as it jumped the fence). So he is scared of any dog that jumps, even in a friendly way out of excitement. This Sacha is a BIG jumper, with long, ungroomed Pit Bull nails. My son also has a fear of dogs in general, unless they are very docile and he is able to approach THEM and work up to comfort. This is not an option with Sacha, she is hyper, jumps like CRAZY, and nobody seems to think this is a problem, nor do they intend to stop her.
My problem is this:
#1: Although I am working on helping my son NOT have an innate fear of all dogs while still maintaining an awareness (because he IS still so young) that some dogs are dangerous, I am not certain that this dog, Sacha, is one that I should be reassuring him is safe.
#2: Because of all of the things I have explained here, do you think that there is a strong potential that (either because my son will project fear, because of the other dogs (the one chow mix and my son are rather close, perhaps competition?), or any other reason, that Sacha MAY turn violent, or hurt my son in any way?
#3: ARE Pit Bulls known to be a violent breed when not properly trained, or is that just a media hype and a complete fabrication, that they are NOT in fact, bred to be fighters?
#4: Do I have a legitimate concern to ask that Sacha be kept in another location/room when we are visiting until my son is older, or maybe anytime we visit, unless they plan to have her professionally trained?
See, I have read hours and hours of literature on both sides of this topic, and I am TORN. I KNOW that Pit Bulls are strong and determined once they begin to fight, but should I fear for my son's safety, or for mine, because this particular dog has been somewhat mistreated and NOT trained by a professional?
How many stories do we read where the dog seemed so nice, and they just snap one day and attack a small child?
Would you take this chance if it were your little one in this situation?

I thank any and all who take the time to read and respond here, I am really trying to be fair and I do not want to make assumptions without doing my homework. Please help me do the right thing. Thank you in advance for your support, and Take Care!

your brother in law had a dog that now your mother and father in law own? if your son is afraid of this dog.. have them put the dog up when he comes over. hes more likely to be bit by that chow thing you own.. look up where the majority of bites come from, its not the pitbull. all dogs can be removed from a situation and cared for and become very well behaved. how old is this dog? if they dont respect you enuff to put the dog away when you and your son come over, how much respect do they have for you.........