It is not puss. It is just scabs. O.K., if you trip and fall and it starts to bleed then when it stops bleeding there will be a scab right? Well if it itches and you scratch the scab off it starts to bleed right? Well that's how Sassy's are. They are mainly located on the back of her neck. There is about 13 of them on her neck, but only about 3 on her back, and just 2 where her tail is.