Is your dog an inside dog or outside?What breed is he?How long has this been going on?
At any point did the whole ear seem puffed up?Is it both ears or just one?
Thanks for answering my questions.
There could be one of two things going on:First, it could be that your dog has been scratching the ear enough to cause trauma to the edges, which could cause them to have that scabby look to them. The fact that it started on one ear and has now moved to the other makes it a bit unlikely that's what we're dealing with.
The other possibility is some kind of disorder or the circulatory system that would compromise blood flow to the edges of the ears. The fact that it started on the left and is now moving to the right makes this more of a possibility to me, but of course, it's impossible to know for sure.
The final possibility is mange since he does come in contact with some wildlife that would carry these kinds of mites. If this were my dog, I would have the ears looked at. Ask the vet to start with a skin scraping to rule out bacterial or yeast infection or mange. If that comes back negative, you may want to start looking a bit deeper, and ask them to run some blood work to look for any anomalies that might be there.
Hopefully they'll be able to figure out what is causing this look.