Yolk sac infection (YSI) and dead-in-shell mortality caused by Enterobacteriaceae in birds are not a rare phenomenon, however there are only a few reports indicating the association between these conditions and Klebsiella spp. among canary chicks (Serinus canaria). There have been reports of high mortality among 1-3 day old canary chicks in an indoor flock of canaries. In order to study the cau...