The possible role of manganese poisoning in enzootic geophagia and hepatitis of calves and lambs.

Aflatoxicosis is known to cause immunosuppression by inhibiting protein and nucleic acid synthesis, which could have predisposed the affected birds to bacterial infection. The 4 principal mycotoxins of concern in birds are aflatoxin B1, ochratoxin A, deoxynivalenol (vomitoxin) and the trichothecenes. The moulds producing these toxins can grow on various feeds, including grains, peanuts, breads, meat and cheese. The birds in this outbreak were fed seeds but the owner would not allow the feed to be examined for mould and it could not be determined whether all the birds received the same ration. As only the breeding birds were affected it is possible that this group was offered supplements not supplied to the other groups. Breeding birds would also have higher nutritional needs and could hence consume higher, possibly toxic levels of toxins present in or on the feed than birds in other groups. The isolation of A. flavus from the liver and gut of the affected birds lends support to a diagnosis of aflatoxicosis. In cases/outbreaks where it is not possible or economically feasible to analyse the feed for aflatoxin mycotoxins, consideration can be given to using standard methods to isolate fungi from the liver and gut. If A. flavus is found this can lend support to the histopathological findings in making a diagnosis of aflatoxicosis.