My year and a half old white German Shepherd has an dark red spot on the skin on the outside of his back leg. I went to the vet for it about a month ago and they said it could be allergies or fleas. They gave me antibiotics which did not seem to help. I also started using his flea and tick medicine which hasn't helped. He has had it for roughly four months now and I'm worried as I have no clue what it could be. It does not seem to bother him whatsoever. Any ideas?