Aggressive Pekingese

Question
I have a 1-year old male Pekingese who previously belonged to my mother.  He has been with us for about two months and for the most part, he usually has a sweet personality.  But he also started showing a very aggressive side to him, it started about two weeks after I got him, during a visit to my mother's.  He tenses up, growls, shows his teeth and then will start biting at his tail, going in circles.  We have taken him to the vet, he has had x-rays, blood work, it all, they can find nothing wrong.  He went about 3 weeks without an episode, but started up again the past few days. He was even doing it in his sleep last night.  When he behaves like this we tell him NO in a stern voice, but it isn't helping.  Any advise??

Answer
This might possibly be a form of seizure or even OCD. Ask your vet if that is a possibility. You might videotape this for them to see, too.

Failing something physical, it could just be stress due to the change in households. Get him into obedience classes and practice "Nothing in Life is Free" with him. http://k9deb.com/nilif.htm

Karen