Luie has a brown spot on his lip. It will dry up, fall off and then come back again. It has been doing this over and over for about 2 months. I took him to the vet and of course the day of our apt. it had just fell off and the vet could not see anything. The vet looked all inside of his mouth and said he could not see anything and that everything inside the mouth looked good. It keeps coming back and it looks brown at first, then it turns black and dries up and falls off over and over again. Other than this spot he is very healthy. Have any of you ever seen anything like this before? Jann