swallowed dog Hair

I basically think you need to train your dog to stop being so aggressive around other dogs. This is dangerous for him as well as the other dogs. He could easily get rabies.
If this is unacceptable behavior is curtailed you could enjoy your walks with your dog even better.
I do not think swallowing hair will cause him to get rabies, but dogs do have sharp teeth and even a light nick that gets a bit of blood is dangerous.
It would help to get your dog an anti rabies shot.