My older dog (7yrs) has started licking our middle dog's (2yrs) penis area. He won't stop. We get onto him and he still does it, the middle dog growls and he still does it. This has been going on for a few weeks and the skin is red and irritated. Is there something we can put on the lickee's skin to soothe it while at the same time deter the licker from licking?