Explainer: On groundhogs, rabies and what we know (and don't know) about Carroll's rodents

This week two groundhogs in Carroll County have caused a stir for what can only be described as odd behavior.

On Sunday, a police officer fatally shot a groundhog in Eldersburg after it caused traffic on a main road, and then scurried toward him when he tried to ward it off the street. A video of the incident has gone viral. On Tuesday, another groundhog in Eldersburg was removed from the area after it charged a woman in a parking lot. Neither groundhog had bit anyone, according to officials, but the two incidents have caused many to speculate: did they have rabies?


According to Joe Mancuso, rabies coordinator for the Carroll County Health Department's environmental health bureau, the results are currently unknown.

Because the first groundhog was shot in the head, Mancuso said any chance at a testing specimen from its brain was compromised, and because there were no reports of anyone in nearby hospitals being bitten by a groundhog, testing was not pursued. The second groundhog, which was reportedly aggressive, has been euthanized and is being tested for rabies. The results should be available within 48 hours, Mancuso said Wednesday.

A groundhog has been removed from the Eldersburg area after it tried to attack a woman in a parking lot Tuesday afternoon, Karen Baker, executive director of the Humane Society of Carroll County, confirmed.

In July 2017, the Maryland Zoo captured a rabid groundhog — not a part of the zoo's collection — on its properties. The wild groundhog was later euthanized and tested positive for rabies.

Still, according to Maryland Department Health data that documents confirmed cases of rabies in animals, rabid groundhogs in the state have not been common.

Of the 2,267 cases of animals that tested positive for rabies in the state between 2011 and 2017, only 40 were groundhogs, according to the department. (Raccoons, however, have accounted for 55 percent of cases.)

And this year, as of May 8, none of the 77 animals recorded as rabid have been groundhogs. Last year, eight groundhogs out of 242 animals were diagnosed with rabies.

"It's rare, but since they're mammals, they can contract it," Mancuso said, and according to wildlife experts, in these two groundhog cases, rabies could be the culprit.

A spokesperson for the Maryland Department of Natural Resources stated in an email to The Baltimore Sun that groundhogs approaching a human — rather than fleeing or retreating — is uncharacteristic. Typically, the rodents are known to stay close to their dens, and unless there is a threat between groundhogs and their home, they retreat into their dens. This behavior is common even during breeding season or when with their offspring. Rabies and distemper, a viral disease that causes fever, coughing and gastrointestinal issues among animals, often show up this time of year, when animals are competing for food, which may cause abnormal responses.


A deputy with the Carroll County Sheriff’s Office fatally shot a groundhog in Eldersburg on Sunday. The incident was captured on video and has been shared widely on social media.

So what do we know about rabies?

  • All mammals are susceptible to the virus, with more than 90 percent of all cases reported to the U.S. Centers for Disease Control and Prevention occurring in wildlife — a major shift from before 1960, when a majority of cases were reported in domestic animals, the CDC stated on its website.
  • The virus is transmitted when infected saliva of a mammal is passed to an uninfected animal, or through brain or nervous system tissue, according to the CDC. The most common form of infection is through bite.
  • Symptoms of rabies can often start with flu-like symptoms, such as weakness or discomfort, fever or headache, which could last for days. Itching sensation or discomfort around the area of the bite may progress within days to symptoms of “cerebral dysfunction, anxiety, confusion, agitation,” according to the CDC. A person may also experience abnormal behavior, hallucinations, insomnia and delirium.
  • The CDC advises people who are bitten by a rabid animal to act immediately. Wash any wounds with soap and water to decrease the chance of infection, and see a doctor before considering the need for a rabies vaccination, known as postexposure prophylaxis.
  • Treatment is often a case by case basis, according to Mancuso. Domestic animals who have bitten someone and are thought to have rabies are put in a 10-day quarantine of testing. If the domestic animal is displaying symptoms, they are euthanized and tested. Wildlife animals that have attacked or come into contact with human are euthanized and tested as soon as they are captured. If the animal is not found, the person who was bitten or exposed to the animal’s saliva will be given the vaccine immediately. “We don’t take any chances,” Mancuso said.