Occurrence of haemolytic Mannheimia spp. in apparently healthy sheep in Norway.

Background: The occurrence of Mannheimia species in healthy sheep has only been investigated to a very limited extend since the genus and its five named species were established. The aim of the present study was to evaluate the occurrence of haemolytic Mannheimia species in apparently healthy sheep originating from four sheep flocks in South-Western Norway.

Methods: Typical beta-haemolytic Pasteurellaceae were isolated from nasal swabs and subsequently subjected to bacteriological examination.