My dog jumped up out of his sleep and started growling at me when I got up he barked at me aggressively as he peed on my pillows.

I don't know that he's sleep walking as much as waking from a doggie nightmare.

One of my dogs (and she was abused) growls in her sleep - if I wake her she'll growl at me for a second before she realizes who I am and where she is.

I'm sure anything is possible.. The brain works the same in all of us.. Overly active brains during the REM period of sleep will make you do anything.. The only difference is, dogs don't know how to deal with things like that. Aggression is triggered by fear.. so if your dog had a "nightmare", fear of whatever happened in his dreams will scare him and he will react accordingly...

I'm a firm believer in never letting a sleeping dog sleep. You should always pet your dog and play with his feet. Always use caution. But owners who never pester their dogs while they are sleeping raise dogs that will bite when touched..