Causes of mortality and culling in adult pheasants.

The causes of the deaths or culling of 155 adult pheasants in breeding pens on one site between 1995 and 1997 were investigated. Approximately half the deaths were the result of problems associated with the reproductive tract or trauma, including injuries acquired during fighting or mating. Sinusitis was the commonest infectious cause of mortality or culling, despite medication of the flocks for mycoplasmosis. Marble spleen disease and pheasant coronavirus-associated nephritis, two viral conditions capable of causing high mortality, were diagnosed in a few birds in 1996 and 1997. Histomoniasis (blackhead) contributed to the mortality in 1996. A lymphomatous condition of uncertain aetiology was detected in a small number of birds.