How severe is the worst manifestation of disease?
If the worst signs in an affected population are limited to mild to moderate oral ulceration, limping and/or URI, then even in the worst case scenario in which an adopter’s pet gets sick, the consequences will likely be limited to a nuisance rather than a life threatening illness. On the other hand, if some cats are getting very sick or dying – whether from virulent systemic disease or “just” horrible oral ulceration – then any exposed cat could transmit severe disease if exposed to a naïve cat. Are otherwise healthy adult cats affected? One of the reasons adopter’s pets at home rarely contract severe disease from newly adopted shelter animals is that the pet’s overall health is good, the animal is not overly stressed, and the pet has not been subjected to the additional environmental factors common in shelters (such as poor air quality) that predispose to serious disease even from relatively mild pathogens. These advantages protect against many infections but not against VS-FCV, which