Susceptibility of Raccoon Dogs for Experimental SARS-CoV-2 Infection

Abstract

Raccoon dogs might have been intermediate hosts for severe acute respiratory syndrome-associated coronavirus in 2002-2004. We demonstrated susceptibility of raccoon dogs to severe acute respiratory syndrome coronavirus 2 infection and transmission to in-contact animals. Infected animals had no signs of illness. Virus replication and tissue lesions occurred in the nasal conchae.

Keywords: 2019 novel coronavirus disease; COVID-19; Nyctereutes procyonoides; SARS-CoV-2; coronavirus; coronavirus disease; raccoon dogs; respiratory infections; severe acute respiratory syndrome coronavirus 2; susceptibility; transmission; viruses; zoonoses.

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.

Figure 2

Detection of severe acute respiratory syndrome coronavirus 2 in swab samples from experimentally infected raccoon dogs. A) Viral genome loads in swab samples isolated on Vero E6 cells; B) viral genome loads in virus titers isolated on Vero E6 cells. Two replicates per sample were analyzed. C) Individual viral loads of nasal swab specimens taken from infected and contact animals.