Quote Originally Posted by Karen View Post
It sounds like separation anxiety - and also, as a Mastiff, he is still a puppy at that age. There are many threads on separation anxiety here, do a search, and you will find many helpful results!

This is NOT an insurmountable problem, I promise!
Exactly my thoughts!

There are a lot of factors going against you:
1) You just moved, and Samson is no doubt incredibly stressed and anxious
2) He is a puppy. An 18-month-old dog is still a baby.
3) Because he's a baby, he's naturally mouthy and energetic. When confined, he's going to mouth things and get into trouble.

I think a muzzle is a fantastic idea, but I'm a little confused. You say you crate him, but it sounds like he escapes from the crate?? If by "crating", you mean just leaving the door open for him, then I suggest you lock him in the crate and begin "alone training". Search this forum for "alone training". It's been covered many times