Ive been having so many problems with our youngest cat, Jasper, who is about 3 I think. I have three boys, they always got on so well, slept together etc but since I have moved house in April last year, he's been getting increasingly aggressive with them.

He wanders ALOT to the neighbours house and wont come home, he is now overweight and I have told them to stop feeding him to no end, but he's not the cat he used to be, he's huge and they think that is normal for a cat. So I have been keeping him inside as much as I can to get him to stay here.

When he is inside with the other two, the first thing he does is look for them and launch onto them and fight them, like right away, the other two run and hide from him.

I dont know why he's started doing this? The other two are at peace with each other and don't cause a problem but clearly Jasper has some major issues