A North Carolina dog that died after suffering an "acute illness" earlier this month has tested positive for coronavirus, officials said Monday.
The death could mark a rare, potentially fatal case of COVID-19 in a pet, though it's still unclear if there were other underlying conditions that contributed to its death.
The dog was brought to the NC State Veterinary Hospital in Raleigh on Aug. 3 after showing signs of respiratory distress earlier that day, the North Carolina Department of Health and Human Services said in a statement.
The person who brought the animal to the hospital told staff members that a family member had previously tested positive for coronavirus, though a later test returned negative results, the department said.
Citing patient confidentiality, the department did not provide additional information about the dog or the person who brought it to the hospital.
The dog died the same day, a department spokeswoman said. Samples taken from the dog that were tested in a diagnostic lab returned a positive result, a result confirmed by the U.S. Department of Agriculture’s National Veterinary Services Laboratory, the statement said.
Investigators were still trying to determine why it died, the statement said.
Only a handful of animals in the United States have contracted the disease, according to a list maintained by the Department of Agriculture. Most of those infections have occurred after contact with people who had coronavirus, according to the Centers for Disease Control and Prevention.
The department says the risk of animals spreading the disease to people remains low.
As of Aug. 7, when the agriculture department’s list was last updated, it had confirmed 13 cases among dogs in eight states, including an earlier positive antibody test in North Carolina. Several cats have also contracted the disease, according to the list. So did eight lions and tigers at the Bronx Zoo.
Last month, National Geographic reported that the first dog to test positive in the United States — a 7-year-old German shepherd from New York named Buddy — died on July 11, six weeks after he was confirmed to have the disease.
The magazine reported that Buddy had lymphoma when he died and it’s unclear how much the cancer and the virus contributed to his death.
Michael San Filippo, a spokesman for the American Veterinary Medical Association, said most dogs that have contracted the disease are asymptomatic or show only slight signs of infection.
That "seems to indicate that this is not a major problem for dogs," he said. "But we have more to learn, like how it might combine with other conditions to cause more serious problems. We’re still advising caution with keeping pets away from people who are ill, and to practice social distancing with your pet and other pets and people outside your household."
This story was originally published on NBCNews.com.