Normally, any animal suspected of having rabies would be taken to a lab for testing, but officials said the beaver sank to the bottom of the lake after being shot and it was not recovered.
The people who were near the animal were undergoing precautionary treatment for possible rabies exposure.
"We want to take every precaution to prevent these individuals from contracting rabies," said Wake County Community Health Director Sue Lynn Ledford. "Anyone visiting Falls Lake and the surrounding areas should be cautious, as rabies is frequently spread from one animal to another, and there may be more infected animals in the area."
Anyone who sees an animal acting in an unusual manner is urged to call Wake County Animal Control at (919) 212-7387 (PETS).