Avian Leukosis Virus Question

[Chickenma65]

Does anyone know how the chickens end up with this disease and how it spreads? My friend got some polish breeds a year ago and she’s lost 3 roosters and now a few hens have tested positive for it. These chickens and roosters are only a year and half old. Some are a bit younger.

 

[azygous]

I have it in my flock. Likely, it came home on the bottom of my shoes after visiting the feed store, and I didn't change my shoes before going out to the run.

It's a durable virus. It can last long enough in the soil and on contaminated shoes to really get around. It's also transmitted from chicken to chicken in dander and feces and during mating. The most tragic transmission is from hen to embryo in the egg. Most of my embryos I try to hatch die in the egg. Of the chicks that survive incubation, half die in the first year.