Hand and Arm Dog Bite Injuries in San Diego, CA Infection Risk and Lost Function

Why the hand is treated as high risk

The StatPearls animal bites review identifies bites to the hands and feet as higher risk for infection because of the small compartments in those regions and the lack of protective soft tissue, and reports that nearly a third of hand bites become infected. The review of mammalian bite injuries to the hand published in the Journal of Hand and Microsurgery records that dog bites account for 80 to 90 percent of mammalian bites and most commonly affect the hand, and that human and animal bites account for 30 to 40 percent of all hand infections. In a retrospective analysis of 525 wounds cited in that review, 14.9 percent of dog bite wounds became infected.

What grows in a hand bite

The same review describes bite wound cultures as typically polymicrobial, with a median of five isolates per wound and 56 percent of cultures growing both aerobic and anaerobic organisms. That mixed picture is the reason a single narrow-spectrum antibiotic is not the standard answer, and it is also why depth matters more than diameter: a small puncture that reaches a tendon sheath introduces that mixture into a space with limited blood supply and no room for swelling.

Irrigation and the closure question

The hand review sets a minimum of one liter of saline irrigation for a bite wound and states that primary closure is relatively contraindicated in hand injuries, citing a 25 percent infection rate reported after primary suture. It contrasts that with superficial head and neck wounds, where plentiful blood supply and appearance justify closure. The StatPearls review adds that infectious disease guidance advises leaving bite wounds open unless there is a cosmetic concern such as the face, that deep puncture wounds and wounds involving a joint space should not be closed, and that closure of an uncomplicated wound may be considered after cleaning and debridement within eight hours. A wound left open on purpose is a treatment decision, and describing it that way in the record prevents it from being read later as neglect.

Prophylaxis carries an unusually clear number

The Cochrane review referenced in the hand literature found a significant reduction in infection after prophylactic antibiotics in bite wounds, with a number needed to treat of four. The pediatric review in Canadian Family Physician reports that prophylaxis lowered the infection rate in hand bites from 28 percent to 2 percent, with the same number needed to treat, and identifies amoxicillin-clavulanate as the first-line agent, generally for three to five days. The StatPearls review likewise treats prophylaxis as warranted for bites that penetrate the epidermis or deeper and names amoxicillin-clavulanate as the preferred choice. Whether it is appropriate for a particular wound is a clinical judgment about a particular patient.

Function is what gets measured later

A hand injury is documented in movement rather than in photographs alone: grip and pinch strength, range at each joint, sensation over each digit, and the tasks a person can no longer perform at the pace they used to. Occupational therapy notes, splinting orders, work restrictions, and a written account of what a shift now requires carry more weight than a general statement that the hand hurts. For trades, clinical work, cooking, cosmetology, instrument playing and keyboard-heavy jobs across San Diego, the loss is specific, and specificity is what a file can preserve.

Why a small wound gets a specialist

The hand literature describes bite wounds over joints as capable of reaching a tendon sheath or joint space through an opening that looks trivial on the surface, which is why an emergency clinician may refer a puncture no larger than a pencil tip to a hand surgeon. The StatPearls review states that wounds involving a joint space should not be closed. Imaging may be ordered to look for a retained tooth fragment or a fracture. None of that follows from wound size, so a record that describes only the size of the opening leaves out the part of the injury that determined the treatment.

The local paperwork still applies

County Code section 62.615 requires a bitten person to notify the Department or the Health Officer as soon as practicable, with the section deeming a failure to report within 24 hours a violation unless earlier reporting was impossible, and County Code section 62.669.1 requires a dog's owner, custodian or other person in control to exercise ordinary care to prevent the animal from attacking, biting or otherwise causing injury to a person engaged in a lawful act. Civil Code section 3342 turns on a bite to a person in a public place or lawfully in a private one, without regard to the animal's history or the owner's knowledge of it. This page summarizes published clinical and legal sources as general information, not medical or legal advice, and questions about a specific hand belong to the treating clinician and to an attorney the reader chooses.