Bubonic disease or plague is also called as Black Death. It is a zoonotic disease means caused by the animals, circulating mainly in fleas on small rodents. The bacteria that is responsible for this disease is Yersinia pestis. This disease occurs by the biting of infected rodents. Example: Rat.Upon a rat bite on a person\’s leg or arm leads to swell up into a painful bulging welt. If left untreated, symptoms, such as vomiting, abdominal pain, and diarrhea, can progress rapidly to septicemic plague. More painful welts would appear all over the person\’s body until the infection was so bad that the person died usually within three days.