My cat is now about 2 years old and I've had him since a kitten, He was the runt of the litter with one of his Dad being a stray. All was fine he used to play nicely with everyone, but now will only play with and accept a stroke from me, He even follows me like a dog. But anyone else even looks like there going to pet at him he goes mental hissing growling etc. He's even chased a friend round the flat trying to attack him. He's perfectly healthy had all his injections and has been done when i first got him as a kitten. He's a big cat and I'm scared he will do someone some damage. So anyone know how I can get him to be a little more social with other people?