Resembles a German Shorthaired Pointer or Blue Tick Hound based on the color markings. But, the ears are too short for either of those breeds. Probably a mix. I don't think it resembles a pit bull.
Definitely looks like a mix. Looks a lot like my Blue Heeler mix except for the ear shape. The picture is when she was a puppy so her head looks a bit more like your picture now.
I photographed a dog in the studio yesterday who looked a lot like that dog. It was a Catahoula Leopard Dog. He was apparently rescued from Mississippi where the breed originated. Don't know for sure but maybe?
Sorry I had to sign off last night. Thank you everyone for your input, I think most of you are right and have triggered my memory as to the owner saying it is a mix. Nice to know what is in the mix! I will close this now, thanks again!