OVERVIEW: Pasteurella species are part of the normal oral flora of cats. They are also a common cause of infection in this species and an important zoonotic agent. INFECTION IN CATS: Pasteurella species are commonly isolated from subcutaneous abscesses and pyothorax in cats. They may also cause secondary lower respiratory tract infection and have been associated with spinal empyema and meningoencephalomyelitis. INFECTION IN HUMANS: Disease in humans mainly occurs after a cat bite or scratch, but may also be transmitted via respiratory secretions from cats in close contact with a person. Signs of local infection after a cat bite appear in a few hours (3-6 h). Severe disease and a fatal outcome mostly occur in immunocompromised people, but have also been reported in immunocompetent healthy individuals. Cat ownership by immunocompromised people may carry a risk.