Rat-bite fever (RBF) is an acute, febrile human illness caused by bacteria transmitted by rodents, in most cases, which is passed from rodent to human by the rodents urine or mucous secretions. Alternative names for rat-bite fever include streptobacillary fever, streptobacillosis, spirillary fever, bogger, and epidemic arthritic erythema. It is a rare disease spread by infected rodents and caused by two specific types of bacteria:

Streptobacillus moniliformis, the only reported bacteria that causes RBF in North America (streptobacillary RBF)
Spirillum minus, common in Asia (spirillary RBF, also known as sodoku). Most cases occur in Japan, but specific strains of the disease are present in the United States, Europe, Australia, and Africa.Some cases are diagnosed after patients were exposed to the urine or bodily secretions of an infected animal. These secretions can come from the mouth, nose, or eyes of the rodent. The majority of cases are due to the animals bite. It can also be transmitted through food or water contaminated with rat feces or urine. Other animals can be infected with this disease, including weasels, gerbils, and squirrels. Household pets such as dogs or cats exposed to these animals can also carry the disease and infect humans. If a person is bitten by a rodent, it is important to quickly wash and cleanse the wound area thoroughly with antiseptic solution to reduce the risk of infection. Symptoms and signs
Symptoms are different for every person depending on the type of rat-bite fever with which the person is infected.
Sesamoiditis is inflammation of the sesamoid bones. Humans
Sesamoiditis occurs on the bottom of the foot, just behind the big toe. There are normally two sesamoid bones on each foot; sometimes sesamoids can be bipartite, which means they each comprise two separate pieces. The sesamoids are roughly the size of jelly beans. The sesamoid bones act as a fulcrum for the flexor tendons, the tendons which bend the big toe downward. Symptoms include inflammation and pain. Sometimes a sesamoid bone is fractured. This can be difficult to pick up on X-ray, so a bone scan or MRI is a better alternative.Among those who are susceptible to the malady are dancers, catchers and pitchers in baseball, soccer players, and football players. Horses
In the horse it occurs at the horses fetlock. The sesamoid bones lie behind the bones of the fetlock, at the back of the joint, and help to keep the tendons and ligaments that run between them correctly functioning. Usually periostitis (new bone growth) occurs along with sesamoiditis, and the suspensory ligament may also be affected. Sesamoiditis results in inflammation, pain, and eventually bone growth. Causes
In humans, excessive forces caused by sudden bending upwards of the big toe, high heels, or a stumble can contribute to sesamoiditis. Once the sesamoid bone is injured it can be very difficult to cure, because additional pressure is put on the sesamoid bone during walking.