Stop in for a cup of coffee

Ok, I just heard this and can't figure it out....

They are going to get "Carona Virus sniffing dogs" to screen at airports etc... They are going to rub a towel/wipe on the passenger and have the dog smell it... So if the dog smells it, and it's transported through the air and can be caught by breathing, what's going to keep the dogs from catching and spreading the virus???? :realcrazy: :wtf:

Saw Branch 02.jpg