Recent encounters with rabid beavers in New York and New Jersey have raised public alarm, prompting warnings from officials and sparking fears of a wider outbreak. However, wildlife experts suggest that while these incidents are serious, they represent isolated events and that the overall risk of rabies transmission from beavers to humans remains extremely low.
Two swimmers were recently attacked by a beaver on Turtle Island in Lake George, New York. One victim described the animal as “out for blood” as he attempted to free his friend from its bites. The New York State Department of Environmental Conservation (DEC) noted that the beaver was later found dead and that it is possible it infected other beavers in the local colony.
This incident followed a May attack in Mahwah, New Jersey, where an 8-year-old boy fishing with his family was bitten by a beaver exhibiting symptoms of hydrophobia, or rabies. Family friends intervened, pushing the animal back into the water. Subsequent tests confirmed the beaver was rabid.
Despite these alarming encounters, experts like Skip Lisle, a wildlife biologist and founder of Beaver Deceivers, a company focused on managing beaver-related infrastructure issues, are hesitant to describe the situation as an outbreak. Lisle stated that rabies in beavers is "extremely, extremely rare in my experience."
Official data supports this view. From 2002 to 2021, only 40 confirmed cases of rabid beavers were reported in New York, and there have been no known instances of rabies transmission from beavers to humans in the state. Felix Lankester, a professor at Washington State University's Paul G. Allen School for Global Health, identified beavers as a "minor vector" for rabies compared to more common carriers such as raccoons, skunks, foxes, and bats. Lankester further explained that beavers are typically infected incidentally and act as "dead-end hosts," meaning there is no self-sustaining cycle of rabies within beaver populations.
Beaver bites, even from non-rabid animals, can cause significant injury due to their powerful jaws, which are capable of felling trees. Medical documentation exists of a man in Massachusetts sustaining multiple deep lacerations from a rabid beaver attack in Connecticut. In a rare fatal incident in Belarus in 2013, a fisherman died after severing an artery while handling a beaver he had intended to photograph.
Beyond rabies, beaver bites can transmit other diseases, including leptospirosis and tularemia. Beavers can also swim at speeds of up to 6 mph, faster than the average human, and may exhibit aggressive behavior if approached too closely, particularly if their lodges and young are nearby.
To avoid potential encounters, the DEC advises boaters and campers to exercise extreme caution and avoid contact with beavers, including carcasses. Lisle recommends observing for warning signs of rabies, such as beavers active during the day (they are primarily nocturnal) or approaching humans on land or in water away from their lodges. He advises leaving the water if a beaver is observed behaving unusually in a public swimming area distant from its lodge.
While specific protocols for fending off a rabid beaver are not as established as those for bears or sharks, one account describes a man using a paddle and later physical force with rocks and a stick to deter an aggressive beaver attacking him and his daughter. Anyone bitten or exposed to a suspected rabid animal is urged to seek immediate medical attention for post-exposure prophylaxis.
Historically, beavers have faced greater threats from humans. Millions were hunted to near extinction by the mid-19th century for the European fur trade, primarily for hat manufacturing. While the fur trade has diminished, beavers are still sometimes killed due to damage caused by dam-building and tree felling, which can lead to flooding. Despite these challenges, Lisle notes that negative interactions with beavers are uncommon, stating he has "never had one hostile interaction with a beaver" throughout his career.