From what I've been told, the shot does't really protect a dog from catching KC, but it does lessen the effects. Maybe my information was wrong, so somebody else can weigh in on this. I asked about it because Tosca had her shot for training but a dog in the class turned out to have it and I was worried. Tosca did not get it, but I was told to still keep my dog away from other dogs for a period of time.