Rat-bite fever is one of two bacterial infections passed through the urine and mucous of certain rodents to humans, including rodents kept as pets. It is usually contracted when a rodent bite breaks the skin rather than through casual contact. The symptoms usually start with inflammation around the site of the bite, which often turns into a rash. That is usually followed by chills, fever, vomitting, headache and muscle aches.As the symptoms are prosaic, the diagnosis is usually confirmed by growing the bacteria in blood culture.