Figure 1.

Study design for experimental infection of raccoon dogs with severe acute respiratory syndrome coronavirus 2. Outline of the in vivo experiment with an observation period of 28 days; 9 animals were inoculated intranasally with 10⁵ 50% tissue culture infectious dose/mL, and 3 naive direct contact animals were introduced 24 hours later. On days 4, 8 and 12, two raccoon dogs were euthanized and autopsied. All remaining animals were euthanized on day 28. Red indicates infected animals.