Gizmo has some problems

So I'm sure everyone is familiar with Gizmo. Well recently he has been out of control and there is just nothing more we can do. One minute he is fine and a happy little dog and the next hes turning on you. Within the past  couple days he has attacked my mom, and two of the cats. It has sadly gotten to the point where we are considering putting him to sleep because hes really just out of control. We are going to see how things go though.
On a lighter note some recent photos of Gizmo.