Not just dogs but people have them as well. Some claim to be able to predict your future from bumps on head, this has been going on for years. Don't worry just formation of the skull . If soft may be a cysts, yes I have had them and when they break on their own, apply rubbing alcohol to clean and then add polysporin to make sure it don't get infected. Heck once I had a huge one and it broke. I freaked and called my doctor. He told me to stay home and apply a warm cloth. Mom made me go to school anyway. How horrible to be in high school and everyone asking why your hair is full of puss. Yikes.