Pasteurella multocida infection of poultry farm rats.

Thirty-four rat carcases from 11 poultry farms were examined for the presence of Pasteurella multocida; 14 out of 34 (41 per cent) proved positive after mouse inoculation, compared with five out of 34 (14 per cent) using media alone. No salmonellae were recovered from 27 rat carcases using enrichment media. Poultry pasteurellosis was present on two farms with infected rats and the same serotype was present in rats and poultry in those cases.