Whose sick???

Not that I'm aware of. Having done rescue with ferals, most of my 6 kittens had URIs when I trapped them. One had a recurrence about a year later. In the 3 years since (4 years total) no one has had one.

Chestnut had one as a kitten (he was a foundling) and again in January 2010 -- he as 12 years old.