[gemy]

Beyond the neutering has anything else changed in the home? Has your bulldog been ill at all?
Obviously you are going to need to stop this behaviour. How have you been discipling Levi for his bad behaviour?
Do you do time outs? Crate or xpen. Do you also use voice commands?

I always ask about exercise; a tired dog is usually a well behaved dog. Are they both getting regular walks at least 30 minutes of exercise a day?

Also it is always a good idea to re-inforce his obedience commands. You can follow the Nothing in Life is free guide to dog training. Most simply put the dog works for every treat and even in the beginning their regular meals. Dog does either sit/down/come/stay/heel what-ever are the commands he knows. Also this is a good time to work more on trick training as well.

In the meantime. I would crate and rotate for both your dogs health , until you get Levi's behaviour under control.