Giovanni,
yes, that's an American Pitbull. Now, just what were you trying to do with those photographs? If you were trying to take a few snapshots of the dog, you got 'em. If you were trying to do a pet portrait, there are some issues you need to address.

1. location. The dog is hot and the lighting is poor.

2. pose. The dog is hot. His ears are back and his tongue is hanging half-way to the floor. Not very flattering.

3. baiting. The dog is looking in a lot of different directions but none of them take advantage of his best feature -- his eyes.

I'd like some text to understand just exactly what you want us to do with these photos. Are you looking for a critique?

Jim