Diseases & Conditions
Each year, millions of people in the U.S. are bitten by animals. Most animal bites occur on the fingers of the dominant hand (the hand you prefer to use for most tasks); however, bites can also frequently occur about the head and neck area and can occur virtually anywhere on the body.
Dogs are responsible for most animal bites, and cats are responsible for the second highest number of animal bites. These typically domestic animals live and interact closely with humans, so it is not surprising that they cause the most bites.
The risk of infection from a cat bite is much higher than from a dog bite. Cats have very sharp, needle-like teeth that can penetrate deep into tissues, bringing infection-causing bacteria with them.
Wild animals can also be responsible for bites. Because most pets in the U.S. are vaccinated for rabies, most cases of rabies in people result from the bite of a wild animal, such as a skunk, bat, or raccoon. Only a few people die from rabies in the U.S. each year, and most deaths are due to bat bites. In countries without robust vaccination programs, dog bites are the most common source of rabies. Rabies causes an estimated 59,000 deaths worldwide each year.
Animal bites may cause crushing and tearing injuries to underlying bone, muscles, tendons, ligaments, and nerves. If the skin is broken, there is the additional possibility of infection.
Symptoms of tissue trauma from bites can include:
- Limb or digit deformity
- Loss of function
Signs of an infection due to an animal bite may include:
- Discharge of pus
- Redness around a puncture wound
- Warmth around the wound
Diagnosis begins with a thorough history to understand when the bite happened, which part of the body is involved, and which animal caused the bite.
- Your physician will ask whether you know the animal that bit you and, if you do, what their rabies vaccination status is.
- If it has been several days since the bite, your doctor will ask whether you have experienced fevers, chills, wound drainage, redness around the wound, and/or other signs and symptoms of infection.
Examination of the injured area will include:
- Inspecting the bite, looking for redness, drainage, and/or swelling (signs of infection)
- Evaluating function, such as making sure the injured area still has feeling, movement, and strength
X-Rays can be helpful to look for injuries to the bones and joints. If your doctor suspects an infection, they may order blood tests and/or more imaging tests, such as an MRI scan or ultrasound. Doctors can see an infection better on MRI or ultrasound than on an X-ray.
Immediate First Aid
- Do not put the bitten area in your mouth. The mouth contains bacteria, which can cause infection.
- Clean any wounds with soap and water or sterile saline, if available.
- If bleeding is severe, apply pressure to the wound with a clean cloth or sterile gauze, if available.
- Elevating the body part that has been bitten may also help with bleeding.
- If bleeding is severe and relentless (will not stop), emergency services may apply a temporary tourniquet.
- If there is a deformity to the bitten area consistent with fracture (for example, a finger looks crooked), a splint can be applied for comfort.
- The area should be washed thoroughly with soap and water or, if available, sterile saline.
- Once clean, the wound can be dressed with sterile gauze.
- Seek prompt medical attention so a medical professional can examine you for signs of more serious injury, such as a fracture, nerve injury, tendon injury, etc.
- Often, the wound will require further cleaning, and you will be treated with antibiotics.
- If your tetanus vaccine is not up to date, you will be given a new dose. If the animal is not known to you or is known to you but is not vaccinated for rabies, rabies prophylaxis (prevention) may be started at this time (including the rabies vaccine).
- In many cases, the physician may leave the wound open (without stitches) to allow it to drain. This is done to help avoid infection. Facial wounds may be cleaned thoroughly and closed.
- As mentioned above, the doctor may order X-rays, blood tests, an ultrasound, and/or an MRI scan to look for treatable injuries and/or infection.
- If the doctor suspects bone, tendon, ligament, vessel, and/or nerve injuries, they may consult with specialists, such as an orthopaedic surgeon, plastic surgeon, or hand surgeon to assist with your treatment.
- Bone: Fractures may require formal debridement (cleaning) in the operating room and may need to be fixed with pins, plates and screws, and/or nails.
- Tendon: Tendon injuries can result in loss of function to the bitten extremity. They may require repair by a surgeon. Tendon injuries often require prompt treatment within a few days of the bite.
- Ligament: Like tendon injuries and fractures, ligament injuries may require surgery. Suspected ligament injuries should be attended to promptly by a medical professional.
- Blood vessel: Vein injuries can often be treated with pressure to stop bleeding. However, injuries to arteries may cut off blood flow to the injured area and may require urgent surgical attention to preserve or restore blood flow.
- Nerve: Nerve injuries can result in loss of feeling or, in some cases, movement of the injured area. These injuries should be assessed promptly by a specialist. It may be possible to repair the nerve; however, even when nerves are repaired expertly and in a timely manner, nerve injuries can require a long recovery and may result in permanent loss of function. Learn more: Nerve Injuries in the Hand and Fingers
- The bite incident should be reported to your local public health department. They may ask for help locating the animal if the animal is not known to you or you are not sure whether the animal has been vaccinated for rabies. Ideally, the animal will be confined (held in a secure place away from humans and other animals) and observed for symptoms of rabies.
Outcomes depend entirely on the underlying injuries caused by the bite.
Minor, superficial bites may result in nothing more than a scar. When not infected, these injuries require little treatment. However:
- Severe bites can cause long-lasting or even permanent issues, such as loss of feeling or decreased function.
- Infections caused by animal bites can be devastating and, in some cases, even life-threatening. Tetanus and rabies are severe infections that are both limb- and life-threatening. If an infection is suspected, it should be treated quickly and aggressively to ensure the best possible outcome.
For these reasons, it is very important to seek prompt medical attention following animal bites.
Contributed and/or Updated by
AAOS does not endorse any treatments, procedures, products, or physicians referenced herein. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance should consult his or her orthopaedic surgeon, or locate one in your area through the AAOS Find an Orthopaedist program on this website.