Fowl cholera

This is a systemic infection caused by the bacterium Pasteurella multocida. Related strains of this bacterium cause respiratory and systemic diseases in a variety of animals including pigs and companion animals but there is no evidence of cross infection by the different types.

Infection occurs generally by the respiratory route but it is really a septicaemia. Disease may be acute with high mortality. Anaemia and diarrhoea occur and excess mucus production from the beak may be evident. Diagnosis from the acute infection can be done with birds that have died from a smear made from the cut liver. This will reveal large numbers of Gram-negative bacteria in pairs surrounded by a capsule which will not be seen with viral infections. A more chronic form of the disease is associated with swelling of the comb or wattles.

It is difficult to eradicate this infection. Antibiotic treatment can stop outbreaks but all birds must be treated since some birds may be carriers.