behavior/personality change in older dog

Question
I have a 9 year old neutered male american eskimo named Kodi. We never took him to an official obedience class as a puppy, but he caught on very quickly to basic commands, and usually followed them on a consistant basis. Around family, he's been a pretty good dog up until recently.
Just in the last few weeks he's been displaying some odd behavior-he's jumping up into the recliner with us without invitation, and is refusing to get back down. You literally have to stand up and dump him out of the chair to get him to get down, when a simple"off" would always do it. He does this like he is afraid of something, when nothing in the environment has changed. He has also been shaking alot. We also used to be able to leave the front door open, and no matter how many family members were outside, he would not step out the front door, even if called. Now, he bolts out to the sidewalk, and recently growled at me when I caught him and tried to bring him inside. He's also displayed sleeping pattern changes. He used to sleep through the night with no problem, but now he wakes us up and when we get up to let him out(he is crate trained and has been his whole life), he often just either wanders around the backyard without needing to go to the bathroom, or he goes to a different spot and lays down. This is if you can even get him to go in his crate for the night in the first place. He was at the vet recently and they didn't find anything physically wrong with him. There haven't been any big changes in the house either. I'm pretty mystified by the sudden behavior changes and was wondering if you might have some theories?
It's like he's turning into a different dog. Thank you so much for anything can suggest.

Answer
Hi Shaini, I have seen some severe personality changes in older dogs that affect their behavior when older, but this does not sound like the case with your dog. Everything you describe sounds to me like a physical problem (cancer, some kind of internal pain...), or a loss of vision or hearing. Please have your vet look further, and consider a second opinion. Did you have his eyes and ears checked as well? Leave me some feedback and follow-up to let me know how things are going with him. Send me further details on what tests your vet ran for you if you need more advice in this area. You could have a local dog behaviorist look at him to confirm my fears as well. Sorry about my delay in writing, had an animal emergency myself. Thank you for writing. Regards, Susan