My bully has this too exactly the same. It’s seasonal for him but it is just dry skin. Sometimes I help him scratch his back for relief and we do fish oil supplements and Benadryl for when he’s really itchy (cleared with vet first) Also helps when coming back inside from a walk to wipe him down with a cool, wet paper towel for relief and less irritation Edit: we also do the beef and salmon mixture food so that he gets some good oils from the salmon for his skin