Welcome to YT. Sounds as though Tober is a puppy, and is trying to play with Dixie. It would probably be best since Dixie is so old; that you try and keep them apart unless you are there to supervise. My older dog jumps up where the pups can't get to him. You might have to help Dixie find a safe place where Tober won't reach her, or she might like to nap in a room you can block off from Tober. Good luck, and just remember Dixie is a lot older, and will need a little help escaping from a puppy she can't really compete with.
Hopefully after a while Tober will grow out of it, and leave her alone.
