Chico has this too! It is gross. I talked to the vet several months ago and he says it is normal and will come and go. There is nothing to do about it. He said that antibiotics would only help on a temporary basis and there was no need for them. He also said he had tried other things for other dogs and it only helps for a little while. I know it is really nasty. We keep antibacterial wipes around to wipe the couch and whatever else he "weenie wipes" as we call it. Chico don't have it all the time. Just comes and goes.