I have a 70 pound Lab/hound (Rodesian Ridgeback) mix. I have noticed that his muzzel/mouth (upper lip) area below his nose is pink colored, and he is lickin the area alot. He seems a bit lethargic at times, but will still chase his toy and play fetch. We live in Freeport Grand Bahama, and he likes to chase/catch Lizzards. What do you think might be wrong? I should add that the area of his muzzle that is pink, used to be a darker color (almost black) like his nose.