Infectious Disease Compendium

Dog Bites

Diagnosis

"I done got bit by a dawg."

Epidemiologic Risks

Either being dumb enough to stick part of your anatomy near a dog or, more likely, another in an endless series of irresponsible dog owners who fail to understand the concept of a leash and let their vermin run free and bite someone.

Microbiology

Streptococci, S. aureus, anaerobes, Pasteurella spp and Capnocytophagia canimorsus.

When tested by 16S ribosome methodology the wounds are filled with difficult to grow anaerobes, that, when grown, are ampicillin susceptible (Pubmed).

Staphylococcus pseudintermedius which can be mistaken as S.aureus (PubMed).

For unprovoked attacks, rabies needs to be considered.

Empiric Therapy

Washing the wound out is key; if the wound is not infected, amoxicillin/clavulanate po is reasonable prophylactic therapy, for the penicillin allergic patient, doxycycline OR a (quinolone PLUS metronidazole). Follow closely and have a low threshold for iv therapy and debridement: third generation cephalosporins PLUS metronidazole, or quinolone PLUS metronidazole.

Specific Therapy

Debride, then Prophylaxis is usually for 10 days. Soft tissue infections (cellulitis or abscess) is iv until afebrile, then po for a total of 10-14 days. Septic arthritis or tenosynovitis is 2 -3 weeks of iv. Osteomyelitis is usually 6 weeks of iv.

Pearls

DO NOT USE first-generation cephalosporins, dicloxacillin, erythromycin. In the asplenic, worry about sudden septic death from Capnocytophagia canimorsus.

Rants

A dogs mouth is not, contrary to popular myth, cleaner than a humans. The difference between a dog bit and a human bite is that the dog bite results in a rapid visit to the ER for care, the human bite is one drunk male punching another drunk male in the mouth, and then passing out in a corner for the rest of the night, with a subsequent delay in therapy and a worser presentation.

Please remember, dogs lick their ass. Bowel flora are therefore a consideration; that people let dogs lick their face is a conundrum I cannot solve.