10. کلینیکی عالیم
Chicken embryos on the right were inoculated via the yolk sac with the Van Roekel strain of
avian encephalomyelitis virus on the 6th incubation day. Control embryos are on the left. The
affected embryos, examined on the 18th incubation day, show extreme muscular dystrophy
(most evident in the embryo with the skin removed) and rigidity of the legs.
17. کلینیکی عالیم
Lens: Locally extensive cataract
Birds that survive the acute infection, may develop cataracts. Here, a
lens opacity, caused by a cataract, can seen in a pheasant.
The lens of this bird's eye contains a large, roughly circular, well-
demarcated pale blue area of opacity.
18. Lens: Focal cataract
Birds that survive an acute infection of avian encephalomyelitis may
develop a blue opacity of the lens, as shown here.
The eye of this bird contains an irregularly shaped, pale blue focus within the lens.