Mortality in fowls due to Aegyptianella pullorum

Abstract

Three outbreaks of Aeqyptianellosis have been described, in the first of which there can be no reasonable doubt that the disease caused very heavy mortality in very young chicks. In the other outbreaks there is evidence to show that A. pullorum may kill older fowls, but apparently not to the same extent as S. anserina. It is interesting to note that under laboratory conditions the disease transmitted by infected A. persicus to chickens three to eight weeks old apparently does very little harm. The factors affecting the virulence of A. pullorum are still obscure, hut the age of the bird appears to be of some importance. The main symptoms in chickens are loss of appetite, dejection and diarrhoea. Sometimes icterus may be noted. At autopsy very young chicks show intense icterus and anaemia, marked tumor splenis, fatty degeneration of the liver, intestinal catarrh, and a characteristic pronounced pale greenish yellow colour of the kidneys. The risk of mortality seems to decrease with age, and then the symptoms and gross post-mortem findings are apparently indistinguishable from those of spirochaetosis.