Animal and Human Bites: When Stitches Are Needed

Topic Overview

A bite injury may need to be closed by a health professional, may require antibiotic medicines, or both. The decision to close a wound with stitches, staples, or skin adhesive depends on:

• The type of biting animal.
• The size and location of the bite.
• The time that has passed since the bite occurred.
• The general health of the person bitten.

It is important to determine if your wound needs to be closed by a health professional. Your risk of infection increases the longer the wound remains untreated. Most wounds that require treatment should be stitched, stapled, or closed with skin adhesives (also called liquid stitches) within 6 to 8 hours after the injury. Some wounds that require treatment can be closed as long as 24 hours after the injury. If stitches may be needed, avoid using an antiseptic or antibiotic ointment until after a health professional has examined the wound.

• Most dog bites can be stitched, especially if the wound is large.
• In general, cat bites are not stitched. Cat bites are usually puncture wounds and can be quite deep. Cat bites have a higher risk of infection than dog bites.
• Human bites are not usually stitched unless they are on the face or ear. Human bites have a high risk of infection.
• Most facial bites can be safely stitched. The risk of infection to the face is lower because the face normally has good blood flow. Because of good blood flow, a face wound may heal faster if it is stitched as soon as possible after a bite.
• Bites to the hand or foot, whether from an animal or a human, are generally not stitched. These bites carry a high risk of infection, and stitching the wound further increases the likelihood of infection. In some situations, a dog bite to the hand may be stitched.

Treatment by a health professional is more likely to be needed for:

• Bites that are more than 0.25 in. (6.5 mm) deep, that have jagged edges, or that gape open.
• Deep bites that go down to the fat, muscle, bone, or other deep structures.
• Deep bites over a joint, especially if the bite opens when the joint is moved or if pulling apart the edges of the bite reveals fat, muscle, bone, or joint structures.
• Deep bites on the hand or fingers.
• Bites on the face, lips, or any area where scarring may be a concern (for cosmetic reasons). Bites on the eyelids often need sutures for both functional and cosmetic reasons.
• Bites longer than 0.75 in. (20 mm) that are deeper than 0.25 in. (6.5 mm) when the edges are pulled apart.
• Bites that continue to bleed after 15 minutes of direct pressure.

Bites such as these should be evaluated by a health professional, but they may not always need stitching.

Treatment by a health professional may not be needed for:

• Bites with smooth edges that tend to stay together during normal movement of the affected body part.
• Shallow bites less than 0.25 in. (6.5 mm) deep and less than 0.75 in. (20 mm) long.
• Bites that are small puncture wounds, such as cat bites.