For the first time in the US, the transmission of COVID-19 from pet parent to pet is documented genetically as part of a study by the Translational Genomics Research Institute (TGen), an affiliate of City of Hope.
The published findings from the ongoing study appear in One Health. This is one of five pilot studies nationwide examining COVID in animals. The TGen study, however, is the only one to include genomic sequencing of the virus from both pet and human samples. This level of testing resulted from TGen’s overall efforts to monitor the virus and its potentially more-dangerous variants by sequencing as many positive human samples of the virus as possible.
In the Arizona case study, the pet owner, cat and dog all were infected with the identical strain of coronavirus: B.1.575, an early and unremarkable version of SARS-CoV-2, the virus that causes COVID. Fewer than 25 documented cases exist of Arizonans infected with this strain, according to information drawn from the COVID variant tracking dashboard that TGen maintains for the CDC and ADHS. To date, more than 46,000 positive samples of Arizonans with COVID have been sequenced.
“This case study was the first example we had from the project that demonstrated the likelihood of virus transmission from a pet owner to animals in the household,” lead author Hayley Yaglom said.
Researchers deduced that the virus spread from the pet parent to either the dog or cat, or both. The animals were confined to an apartment and therefore had little to no opportunity to be exposed to the virus, and so it was highly unlikely that the pets infected their owner. Plus, in each case examined in the study, it was the pet parent who exhibited COVID first. Worldwide, there is no documented case of COVID transmission from a pet to their pet parent.
Researchers were unable to tell if the dog or cat were infected first, or if one infected the other, though that is a possibility. This particular dog and cat were buddies who had close contact with each other, researchers said.
Including this case study, Arizona researchers tested 61 pets—39 dogs and 22 cats—living in 24 households. There were 14 positive cases of COVID in pets among six of the households.
“This is a great example of using genomics to gain intelligence about pathogens,” TGen’s David Engelthaler said.
“This study shows that we can not only use genomics to help track COVID variants across the globe, but we can also use this technology to track exact transmissions, and in this case transmission from pet owners to pets.”