A 7-year old German Shepherd, who in May was the first dog to test positive for COVID-19, died on July 11, according to National Geographic.

“Buddy,” a family pet of the Mahoneys in Staten Island, New York, was euthanized after suffering complications from lymphoma, NatGeo reports, adding that by the time of its death the dog had tested negative for COVID-19 but it’s unknown what role the virus may have played in its lymphoma symptoms, and vice versa.

Medical records provided by the Mahoneys and reviewed for National Geographic by two veterinarians who were not involved in his treatment indicate that Buddy likely had lymphoma, a type of cancer, which would explain the symptoms he suffered just before his death.

The Mahoneys didn’t learn that lymphoma was being considered as the probable cause of his symptoms until the day of his death, they say, when additional bloodwork results confirmed it. It’s unclear whether cancer made him more susceptible to contracting the coronavirus, or if the virus was responsible for any of his symptoms, or if it was just a case of coincidental timing.

Read more at www.nationalgeographic.com