Buddy, a seven-year-old German shepherd, fell ill in April, around the same time that his owner, Robert Mahoney, was recovering from covid-19, the magazine published this week.

The animal appeared to have a stuffy nose and shortness of breath, and its condition continued to deteriorate over the weeks.

Mahoney and his wife Allison, who live in New York City, finally decided to put him down on July 11, when Buddy started vomiting blood clots, had blood in his urine, and was unable to walk.

The family told National Geographic that they suspected Buddy was infected with the SARS-CoV-2 virus, but that this had been difficult to confirm.

Without a doubt, I thought it was positive, Mahoney said, but many vets in her area were closed because of the pandemic. Others were skeptical of the possibility that an animal had covid-19.

A clinic was finally able to confirm that Buddy was truly infected, and that the other family pet, a 10-month-old cub who had never been sick, had antibodies against the virus.

Doctors who treated Buddy later found that the dog probably also had lymphoma, which could indicate that, like humans, animals with other ailments are more likely to become seriously ill once contracted with the new coronavirus.

According to the World Health Organization (WHO), pets do not usually transmit the virus to their owners.

But Shelley Rankin, a veterinarian at the University of Pennsylvania, said more study is needed to make that clear.

If we are telling the world that the prevalence (of animal cases) is low, then we have to study a large number of animals, she said.

Twelve dogs and 10 cats have tested positive for coronavirus in the United States, according to National Geographic.

The Mahoneys said they want Buddy's story to be known. He was well liked. I wish we could have had him longer, Allison said.