[theBCnut]

Um, did you feel it? Pus isn’t usually that thick in dogs. It could have been a kitty claw mark that healed over before bleeding enough to clean out, but from your description, my first thought was sebaceous cyst. Almost always infected areas are hot and drop all the hair. When they rupture, the skin over it thins out until it ruptures and then it’s a sloppy oozy mess. Also extremely painful before rupturing.