There are an estimated 3-6 million animal bites per year in the United States, of which 80-90% are from dogs, 5-15% are from cats, and 2-5% are from rodents. Cats more frequently bite women than men. All bite wounds that break the skin should be evaluated immediately by a physician, physican assistant, or nurse practitioner. The most common complication of these bite wounds is deep soft tissue infection and this is the focus of this article.
Cat bites are associated with a higher risk of infection because they have sharp, needle-like teeth. The teeth create deep puncture wounds, placing bacteria from the cat’s mouth into direct contact with the deep soft tissues. In some cases, the bacteria are injected into the bones and joints, creating a condition called osteomyelitis (infection of the bone) or septic arthritis (infection within the joint space). Cleansing the wound surface with soap and water is often not effective in preventing infection because of the inoculation of bacteria into deeper tissues.
When treating a cat bite, the following information is important in making treatment decisions:
- Time and location of bite
- Health status of cat, rabies vaccination history, behavior, whereabouts, etc.
- Circumstances surrounding the bite (ie, provoked or defensive bite versus unprovoked bite)
- Location of all bites
- Patient’s medical history
If there are any signs of a puncture wound, a more aggressive surgical debridement and formal washout should be considered early. Other indications for surgery include associated injuries to blood vessels, nerves, tendons, bone or joints.
Antibiotics are necessary in nearly all cases of cat bites. Penicillin-based medications are the preferred first-line medication for treatment of infections. Amoxicillin and Amoxicillin-Clavulanic Acid are the most common antibiotics used in the treatment of cat bite associated infections. For patients with penicillin allergies, fluoroquinolones (for example ciprofloxacin or levofloxacin) are acceptable alternatives. Antibiotics need to have coverage against Pasteurella multocida, a bacteria that is part of the normal oral flora of both cats and dogs. The majority of bites and infections can be treated on an outpatient basis with close follow up, especially when treatment is initiated the same day as the bite. Approximately 6% of cat bite wounds, however, will require hospitalization for extensive surgical debridement and intravenous antibiotics. Early recognition and treatment are therefore paramount to ensure optimal outcomes from these potentially devastating infections.
David Mokhtee, MD
Surgery of the Hand
Northwest Hand and Orthopedics
Shoreline, Woodinville and Everett/Mill Creek