Infectious Disease Compendium

Animal bites

Diagnosis

"I was bit by a ....." fill in your blank. Humans, while animals, are covered here: Bites, human.

Epidemiologic Risks

Sticking your hand near the mouth of an animal.

Microbiology

Depends on the animal, that list is here: Zoonosis. For cats and dogs Pasteurella, anaerobes, streptococci lead the list.

Empiric Therapy

Amoxicillin-clavulanic acid for most bites after wound cleaning and tetanus shot. Rabies issues here. Usually worry about rabies from an unprovoked attack: if you interact with the animal in any way, then it is usually not considered unprovoked.

Cat bites

Amoxicillin-clavulanic acid for prophylaxis.

For real infections use real antibiotics directed against the flora of a cat mouth: (ampicillin OR third generation cephalosporins) PLUS metronidazole would be good choices. If PCN allergic use (doxycycline OR a quinolone) AND (clindamycin OR metronidazole). Pasteurella are usually resistant to first generation cephalosporins.

Dog Bites

Amoxicillin-clavulanic acid for prophylaxis.

For real infections use real antibiotics directed against the flora of a dogs mouth: (ampicillin OR third generation cephalosporins) PLUS metronidazole would be good choices. If PCN allergic use (doxycycline OR a quinolone) AND (clindamycin OR metronidazole). Pasteurella are usually resistant to first generation cephalosporins.

In splenectomy, they can flame out from sepsis from Capnocytophagia canimorsus. It should be sensitive to near about all beta lactams.

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. And do not forget the tetanus shot.

Pearls

Pasteurella usually occurs in the first 48 hours after a bite.

Zombie bites? Nothing to do. You will become one yourself, feasting on brains, until a gunshot to the head. Unless you follow the results of When zombies attack!: Mathematical modelling of an outbreak of zombie infection.