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. The same preliminary, unreviewed study that found cats susceptible in the laboratory also found that the virus reproduces poorly in dogs, pigs, chickens and ducks.

Among animals that may be used in laboratory tests, the novel coronavirus infects genetically engineered mice as well as some monkeys. Chimpanzee sanctuaries in the United States have stopped tours and reduced staff members’ interactions with their animals in case apes may be vulnerable, too.

Ferrets are yet another potential laboratory animal. A report accepted for publication in Cell Host & Microbe documents that ferrets both become infected and pass the virus on to one another, showing some symptoms similar to those of humans, such as a fever, lethargy and coughing. All the animals recovered, however.

Jae Jung, a microbiologist at the Keck School of Medicine at the University of Southern California, was one of the authors on that paper. He said that mice are likely to be on the front lines of testing, particularly for new drugs or vaccines. Established drugs or vaccines that are similar to previous ones used in humans may go straight to human trials.

In genetically engineered mice, the virus appears in all cells, and the symptoms of the mice are not similar to those of humans. Monkeys, Dr. Jung said, are close to humans, but they can be used only in small numbers. Ferrets are particularly useful, because, like monkeys, they do not need to be genetically engineered, but they are easier to raise in a lab than monkeys and the structure of their breathing system is similar in some ways to that of humans. They become infected in the lungs, as humans do.

Ferrets have been used in influenza research and in research on SARS, partly because they cough and, Dr. Jung found, can pass the virus to one another. They may be useful to study how the virus is transmitted.

Dr. Jung said the ferrets showed a fever and lethargy and “occasionally coughing.” Around Day 10 or 12 of infection, he said, “they all recovered.”