Rat bite fever is a rare infection typically caused by Streptobacillus 
moniliformis. The mode of transmission is most commonly through a bite or 
scratch from an infected rat. This disease is characterized by polyarthritis, 
fever, and a delayed onset erythematous maculopapular rash of the extremities. 
The authors report a case of rat bite fever, which led to septic arthritis of 
the hip. To the authors' knowledge, the complication of hip sepsis requiring an 
arthrotomy has not been reported in the literature. The orthopaedist should be 
aware of not only Streptobacillus moniliformis, but also of other zoonotic 
organisms, which potentially can cause septic arthritis and warrant treatment 
with specific antibiotics.