Thanks CharlieI ran into this exact same problem a couple years ago. Even same thing with my dog.
After a little research I learned that smoke can not be effectively filtered because it's not just particulates but also gasses and the gasses are too small for a media filter.
So, with smoke, you have to neutralize it or get rid of it.
Lots of good suggestions for the inline fan that goes outside. They suck a lotta air and can effectively clear a room of smoke..
I ended up doing what was posted above. An activated carbon filter attached to one of my old 6" inline fans. Works amazingly well. I didn't use a box or anything. Just Nomad with his spinning hat. LOL I actually think it looks kind of cool. LOL
Good luck with your dog.
I am the same guy who posted about my dog
So did you vent yours outside of house, and did dog respond Good?
Thks