American Pit Bull x Mastiff in risk of being put down?!?

I don't understand this clearly. It seems to be a dispute between your brother and his In-laws. But suddenly, the Concil (?) is involved. Do you mean a town or village Council? If city officials are involved -- that must mean that Baxter violated some law or attacked some person. That casts completely different light on your story. Or do you mean a family council to decide Baxter's fate? Your brother owns him -- so he should be safe. If a Council is involved - then your brother needs legal istance; sorry hon - but you can't help in this situation other than to support him.