Which animal bites require post-exposure prophylaxis (PEP) with anti-rabies vaccine?

Animal Bites Requiring Anti-Rabies Vaccine

All bites from wild terrestrial carnivores (raccoons, skunks, foxes, coyotes), bats, and wild animal hybrids require immediate post-exposure prophylaxis unless the animal is available for testing and proven negative for rabies. 1

High-Risk Animals Requiring Immediate PEP

Wild Terrestrial Carnivores

• Raccoons, skunks, foxes, and coyotes are the most commonly rabies-infected terrestrial animals in the United States. 1
• All bites by these animals must be considered rabies exposures and PEP should be initiated immediately. 1
• These animals should be euthanized and tested; if testing is negative, PEP can be discontinued. 1
• Clinical signs of rabies in wildlife cannot be reliably interpreted, so any exposure warrants prophylaxis. 1

Bats

• Bats are documented rabies reservoirs in all 49 continental United States and require PEP for any bite, scratch, or mucous membrane exposure. 1, 2
• PEP should be considered even when a bite is not apparent if direct contact occurred and the exposed person cannot be certain no bite or scratch happened. 1
• Special situations requiring PEP include: a sleeping person awakens to find a bat in the room, a bat is found with an unattended child, mentally disabled person, or intoxicated person. 1, 2
• Bat bites can be minor and easily undetected, making them particularly dangerous. 1, 2, 3

Wild Animal Hybrids

• Offspring of wild animals crossbred with domestic dogs or cats are considered wild animals. 1
• These animals should be euthanized and tested rather than observed when they bite humans. 1

Conditional Risk Animals

Domestic Dogs, Cats, and Ferrets

• A healthy domestic dog, cat, or ferret that bites can be confined and observed for 10 days rather than immediately starting PEP. 1, 3
• Begin PEP immediately if the animal shows any signs of rabies during the observation period. 3
• If the animal is rabid, suspected rabid, or unavailable for observation, initiate PEP immediately. 3
• Regional variation exists: rabies in dogs is most common along the US-Mexico border; more cats than dogs were reported rabid in the 1990s in the US. 1
• In developing countries where dogs are the major rabies vector, exposures to dogs represent significantly increased risk. 1, 3

Woodchucks

• From 1990-1996, woodchucks accounted for 93% of rabies cases among rodents in areas where raccoon rabies was endemic. 1
• Consult state or local health department before deciding on PEP for woodchuck bites. 1

Animals Almost Never Requiring PEP

Small Rodents and Lagomorphs

• Small rodents (squirrels, hamsters, guinea pigs, gerbils, chipmunks, rats, mice) and lagomorphs (rabbits, hares) almost never require anti-rabies prophylaxis. 1, 4, 3
• These animals are rarely infected with rabies and have not been known to transmit rabies to humans in the United States. 1, 4
• State or local health department should be consulted in all cases involving rodent bites. 1, 4

Type of Exposure Considerations

Bite Exposures

• Any penetration of skin by teeth constitutes a bite exposure requiring evaluation. 1
• All bites, regardless of body location, represent potential rabies transmission risk. 1

Non-Bite Exposures

• Scratches, abrasions, open wounds, or mucous membranes contaminated with saliva or neural tissue from a rabid animal constitute non-bite exposures. 1, 3
• Non-bite exposures from terrestrial animals rarely cause rabies but should be considered for PEP. 1
• Contact with blood, urine, feces, or petting a rabid animal does NOT constitute an exposure and is not an indication for prophylaxis. 1, 3
• Dried material containing virus can be considered non-infectious. 1, 3

Critical Pitfalls to Avoid

• Do not confuse management of small rodent bites (which rarely require PEP) with bat or wild carnivore bites (which almost always require PEP). 4, 2
• Do not fail to consider PEP for bat exposures when a bite cannot be definitively ruled out, especially in sleeping persons or children. 2
• Do not delay wound washing while arranging for PEP; immediate thorough washing with soap and water for 15 minutes is the most important first step. 4, 3
• Do not wait for animal testing results to initiate PEP for high-risk exposures; treatment can be discontinued if testing is negative. 1, 2