Animal Bites (Cat, Dog, Monkey, Lizard, Snake)

Quick bullets to prep for in-training, let’s review

Management for ALL animal bites

  • X-ray if suspect foreign body
  • Remove teeth
  • Routine wound care/irrigation
  • Update tetanus



  • Pathogens: Pasteurella, Bartonella (cat scratch)
  • Treatment
    • Leave the wound open (don’t suture)
    • Strongly consider antibiotics for ALL bites
      •  Amoxicillin/clavulanate
      • PCN allergic: Metronidazole or Clindamycin AND doxycycline, trimethoprim-sulfamethoxazole, moxifloxacin, or cefuroxime



  • Pathogens: Staph and Strep most predominant, Pasteurella
  • Treatment
    • Primary closure if on cosmetic part of the body
    • Antibiotics only if signs of infection, comorbidities, large wounds with gross contamination, wounds on the hand, delayed presentation
      • Amoxicillin/clavulanate
    • Rabies immunoglobulin and vaccination if unknown vaccination status of the dog



  • Pathogens: Herpes B, Rabies
  • Herpes B virus
    • Found in Macaques
    • Fatal if untreated
    • Paresthesias > vesicles > encephalitis
    • High infection rate if untreated
  • Treatment:
    • Leave the wound open (don’t suture)
    • Acyclovir for herpes prophylaxis
    • Rabies immunoglobulin and vaccination
    • Consider bacterial prophylaxis



  • Venomous: Mexican beaded lizard, Gila monster
  • Symptoms: Local symptoms, nausea and vomiting, rarely hypotension
  • Treatment
    • Observe for 6 hours for systemic effects
    • If hypotensive treat as if anaphylactoid reaction with IVF, epinephrine, steroids, antihistamine
    • Antibiotics only if signs of infection, comorbidities, large wounds with gross contamination


Snakes (US)

  • 4 Families
    • Viperidae
      • Crotalinae > Pit vipers
    • Elapidae
    • Colubridae
    • Atractaspidinae
  • Viper Family / Pit Vipers
    Ref 3
    Ref 3
    • Includes: Rattlesnakes, cottonmouth, copperheads, western diamondbacks
    • Account for the majority of snake envenomations in North America
    • Identification
      • Triangular shaped head
      • Nostril pits
      • Elliptical pupils
    • Majority are dry bites
    • Local effects
      • Severe pain
      • Edema
      • Erythema
      • Rhabdomyolysis
      • Compartment syndrome
    • Systemic effects
      • Paresthesias
      • Generalized weakness
      • Chest pain
      • Thrombocytopenia, bleeding complications
    • Testing: CBC, fibrinogen, PT, PTT, INR
    • Treatment
      • If asymptomatic observe for 8 -12 hours and repeat blood work
      • Supportive care
      • Moderate to severe envenomations may use Croatlidae polyvalent immune Fab (CroFab)
  • Elapidae
    Ref 3
    Ref 3
    • Coral snakes
    • Identification: red on yellow kills a fellow; red on black, venom lack.
    • Symptoms
      • Neurotoxicity – paresthesias, fasciculations, slurred speech, ptosis, diplopia, dysphagia, stridor, paralysis, respiratory failure from neuromuscular blockade
      • Serious neurotoxicity may initially be asymptomatic for a number of hours
    • Treatment
      • Antivenin if strong suspicion of coral snakebite, even in absence of signs of envenomation
      • Admit for monitoring given risk of delayed neurologic manifestations and respiratory failure

Note: All fuzzy animals are nice and haven’t bitten people.


  1. James Q. Puncture Wounds and Bites. In: Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8e. New York, NY: McGraw-Hill; 2016. Accessed January 05, 2017.
  2. Johnston WF et al. Exposure to Macaque Monkey Bite. J Emerg Med. 2015; 49(5): 624-7. PMID: 26281802
  3. Ruha A, Pizon AF. Native (US) Venomous Snakes and Lizards. In: Hoffman RS, Howland M, Lewin NA, Nelson LS, Goldfrank LR. eds. Goldfrank’s Toxicologic Emergencies, 10e. New York, NY: McGraw-Hill; 2015. Accessed January 05, 2017.
May 2024