Ear is red inside and he shakes his head all the time and sometimes he takes his paw and digs it like it itches

It could be mites or an infection.

Time for a vet visit to determine the cause and get prescription ear drops for him.
With ear drops it should clear up within a few days.

I agree. I'd bet on mites, which is actually fairly common in doxies. Both of mine have had it and my mom's had it. Is there's a lot of brown discharge or a bad smell coming from his ears? You can buy over the counter eardrops for it, but you'll want to get it diagnosed first.