2.1 Animal Experiment
The animal experiments were conducted under the approval of the Canadian Science Center for Human and Animal Health Animal Care Committee which follows the guidelines of the Canadian Council on Animal Care. To determine if domestic poultry are susceptible to SARS-CoV-2 infection, fourteen 4- to 6-week-old leghorn chickens (Gallus gallus domesticus ) were acquired from the CFIA SPF flock in Nepean, Ottawa and fourteen 4-to 6-week-old turkey (Melleagris gallopavo ) pullets were purchased from a local turkey breeder in Manitoba. Both turkeys and chickens were kept for a week in biosafety level 3 animal cubicles for acclimatization for a week. After a week, both turkeys and chickens were split into 2 groups (SARS-CoV-2 and control). Prior to infection, blood, oropharyngeal and cloacal swab samples were collected from SARS-COV-2 and control group chickens. Ten chickens and 10 turkeys were inoculated using a combination of natural routes of infection (combination of oral, nasal and ocular) with one ml containing 106 plaque forming units per ml (PFU/ml) of SARS-COV-2 virus. Control groups were mock inoculated using same routes with PBS. Oropharyngeal and cloacal swabs were collected from infected and control groups at 2, 4, 6, 9 and 12 days post-inoculation. Two chickens and two turkeys were euthanized on 3, 5, and 7 days post-inoculation and tissues samples were collected (brain, thymus, trachea, lungs, spleen, duodenum, cecal tonsil, liver, kidneys, bursa and heart).