Dr. Calle said, however, “There’s no evidence anywhere, other than the initial spillover, that any animal has infected any person anywhere. So you do have to put things in perspective.”
The U.S. Department of Agriculture, the World Organization for Animal Health and the American Veterinary Medical Association all state on their websites that there is so far no evidence that domestic animals can pass on an infection to people. They all advise, however, that anyone who is sick should take the same precautions about contact with their pets that they would with humans.
“There’s still a lot we don’t know,” Dr. Terio said. “We’re all trying to play catch up and learn about this virus in real time, as things are happening.”
Dr. Epstein emphasized that it was still unclear what level of infection cats may have and whether they may transmit it to each other, which has been suggested. He said that the worldwide pandemic is being driven by human-to-human transmission, but advised, as others do, to “treat cats as other family members.”
“There’s no evidence yet that cats can transmit this virus to people,” he said. “But you don’t want to take this chance in the absence of information.”
Scientists at various labs are looking at animal susceptibility, both in terms of pets and with an eye to what animals could be used in laboratory studies. A preliminary, unreviewed study suggests that the virus reproduces poorly in dogs, pigs, chickens and ducks.
Among animals that may be used in laboratory tests, the virus infects genetically engineered mice, as well as some monkeys. A report accepted for publication in Cell Host & Microbe documents that ferrets both become infected and pass the virus on to each other, showing some symptoms similar to humans, such as a fever, lethargy and coughing. All the animals recovered, however.