MY FRIEND HAS A BULL MASTIFF DOG 2 YRS OLD, HE IS GETTING QUITE AGGRESSIVE, WHEN MY FRIEND TAKES HIM OUT IN HER CAR HE STARTS BARKING AT HER IF SHE TELLS HIM OFF HE DOES GET A BIT AGGRESSIVE, SHE HAS BEEN TAKING HIM IN THE CAR SINCE HE WAS A PUPPY, SO WE DONT KNOW WHY HE'S STARTED DOING THIS, I HAVE TRIED TAKING HIM IN MY CAR AND HAVE NO PROBLEMS WITH HIM, ALSO SINCE THE AGE OF 18 MONTHS HE HAS BEEN GETTING AGGRESSIVE AT HOME AS WELL. SHE TAKES HIM TO DOG TRAINING EVERY WEEK, WITHOUT FAIL, THE DOG TRAINER ADVISED HAVING HIM CASTRATED, SO SHE CONSULTED HER VET ABOUT THIS, HE SAID IT MIGHT CALM HIM DOWN. SO SHE HAD THE OPERATION DONE. IF ANY THING HE'S WORSE. MY FRIEND WAS DECORATING HER HOME RECENTLY, AND ASKED ME TO LOOK AFTER HER DOG FOR A WEEK, WHICH I DID. DURING THIS WEEK I COULDNT OF ASKED FOR A BETTER DOG, NOT ONCE WAS HE AGGRESSIVE TOWARDS ME, MY CHILDREN, OR MY OWN DOG. BUT AS SOON AS HE WENT HOME HE STARTED AGAIN. PEOPLE SAY WHY DONT I JUST LET HIM LIVE WITH ME, I CANT, I ALREADY HAVE AN ENGLISH MASTIFF, AND HE TAKES UP ENOUGH ROOM FOR 5 DOGS. PLUS MY FRIEND LOVES HER DOG AND DOESNT WANT TO PART WITH HIM. PLEASE HELP