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.