The dog, Winston, was part of a Duke University study in which a family in Chapel Hill, the McLeans, were tested for the virus.
The mother, the father, the son and the pug tested positive, while the daughter, another dog and a cat tested negative, according to NBC affiliate WRAL of Raleigh.
Dr. Chris Woods, the principal investigator for the Duke study, said Winston may be the first dog in the country to have a confirmed case of the virus.
The mother, Heather McLean, a professor of pediatrics at Duke University School of Medicine, told WRAL that Winston has had mild symptoms.
"Pugs are a little unusual in that they cough and sneeze in a very strange way," she said. "So it almost seems like he was gagging, and there was one day when he didn't want to eat his breakfast, and if you know pugs, you know they love to eat, so that seemed very unusual."
Ben McLean, her son, said it made sense that the dog got the virus because the pet "licks all of our dinner plates and sleeps in my mom's bed."
While Winston may be the first dog in the U.S. known to have tested positive for the virus, a 17-year-old dog in Hong Kong with the coronavirus died last month, although the cause of death was unclear, as the owner refused an autopsy.
Guidelines on pets from the Centers for Disease Control and Prevention say "there is no evidence that animals play a significant role in spreading the virus that causes COVID-19," but the CDC recommends that you treat them "as you would other human family members."
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"Do not let pets interact with people or animals outside the household," the center says. "If a person inside the household becomes sick, isolate that person from everyone else, including pets."
Heather McLean said she hopes the study will shed more light on how animals fare if exposed to the coronavirus.
"I think because there's not a lot of studies and sampling of pets, we just don't know yet," she said. "My advice is just not to get too worried about it."
CORRECTION (April 28, 2020, 11:55 p.m. ET): An earlier version of this article misspelled the name of the family who own Winston. They are the McLeans, not the McCleans.