Ive been disturbed watching Maxwell having deep breathing sleep followed by agressive `attack` actions (snarling/biting)  which wake him up and scare the life out of the rest of us and poor Bella (luckily none of us have been in close enough range for injury) - happens around 730pm - 3 weeks on the run - he is obviously distressed afterwards due to the shock wake up - but 3wks on the run ? whats going on? he isnt friendly at all with strangers & only accepts people he knows - its taken the cleaner 3 months for him to allow her to touch him.

he had another nasty nightmare last night (which is no fun as he sleeps on the bed) and one this morning .. is there any connection that over the last 3wks he hasnt had so much outside exercise due to the snow? getting more frequent is worrying me :(

Are you sure it isn't fits he is having?

he just wakes in a shocked state growling/snapping ... i would imagine fitting would involve shaking etc ? - it only last 3-4 seconds till he wakes up fully.

I would want to rule out health problems.  A vet visit first I think.

I agree, get vet to check him out....but just be careful if he sleeps on the bed....was a woman on This Morning a while back, who had by all accounts a lovely dog, then one night while in bed, he attacked her bigtime for no apparent reason, and she concluded that he had had a nightmare....so she was warning people to just be careful if they have dogs sleep on the bed with them.  Probably a freak accident type of thing, but shows it could happen..