What is the cheapest, simplest way to freshen up the wood on this sofa?

I have a couch that has a wooden frame, arms and legs, and a cushioned seat.
It was given to us by someone that owned large dogs, so the wood was not beautiful to begin with. Ultimately, we use the sofa for our dogs. It is really the dogs’ couch. It keeps them off of our nicer furniture, and they have a spot to sleep.
Both arms, which are wood, are pretty scuffed and scratched after several years of the dogs hopping up and down. I do not want to invest a lot of time or money into fixing this, but I am getting sick of looking at the damaged arms. Since, it is going to remain a spot for the dogs to lie, I don’t want to replace it.. but I would like to camouflage some of the damage, if possible. Just so that it doesn’t look like a piece of junk in my computer room.
Can I just scrub it down and put a coat of stain on it? If so, what kind? Should I attempt to match it to the current shade of wood, or go lighter? Darker?
I don’t want to strip it and/or sand it. It’s not even remotely that important to me. :)