Managing A Case Of Dog Bite

A 50-year-old man is brought to you in ED after being bitten by a stray dog. The bite was unprovoked and is on the abdomen. The patient has no other health history of note and has not taken antibiotics for over a year. You irrigate the wound and are deciding about closure. There is a 3-cm laceration on the abdomen.

All of the following are true about dog bites EXCEPT:

A) They tend to be primarily crush-type injuries.
B) In general, the infection rate is similar to a laceration from any other mechanism (e.g., knife cut),
except on the hands and feet.
C) A common organism in infected dog bites is Staphylococcus aureus.
D) Primary closure of dog bite wounds is an acceptable
option (except perhaps on the hands and feet).
E) They always require antibiotics.

Answer And Discussion

The correct answer is “E.” All of the rest are true statements.

Dog bites (except for those from little poodles named Fifi) tend to be crush injuries (as contrasted
with cat bites, which are primarily puncture wounds). The infection rate is about the same as other lacerations. Bites on the hands and feet tend to have a higher rate of infection. Most dog bite infections are polymicrobial with S. aureus playing a large role, and Pasteurella and Capnocytophaga playing a smaller but significant roles. Other organisms include Streptococcal
species and gram-negative species. Dog bites do not generally require antibiotic prophylaxis, except under certain circumstances (e.g., present >9 hours after bite, immunocompromised, large or complicated wound).

You are concerned about rabies prophylaxis. Which of the following is the best next step?

A) Isolate the suspect animal for 3 days.
B) Sacrifice the suspect animal and examine the liver.
C) Administer rabies immune globulin IM.
D) Administer rabies immune globulin IV followed by rabies vaccination series.
E) Administer rabies immune globulin by infiltrating it around the wound followed by rabies vaccination series.

Answer And Discussion
The correct answer is “E.” Administer rabies immune globulin by infiltrating it around the wound followed by rabies vaccination series.

You should infiltrate rabies immune globulin around the wound and then begin the rabies vaccination series. As much of the immune globulin as possible should be infiltrated around the wound and the rest should be given IM at a different site.

“A” is incorrect because animals need to be isolated for 10 days, not 3.

“B” is incorrect. The animal can be sacrificed but the brain should be examined—not the liver.

 “C” and “D” are both incorrect methods of administering the vaccine/immune globulin.