Leucosis is relatively short lived in the environment, a few weeks as opposed to up to a year or more with Marek's. Therefore, if the entire flock dies, three weeks or so and the virus is gone from the soil and lingering dust. Then I could start a new flock.
No one can diagnose from a couple of photos. It requires pathology tests to confirm it. Leucosis is a possibility is all we can say.
I love my chickens and love having baby chicks. I have given up hatching from my flock since leucosis has been confirmed, but I still get new chicks every year or...
Your entire flock carries the virus. But if it's leucosis and not Marek's, your flock can lead mostly normal and long lives once you accept the limitations. It would be a good idea if you were to send this dead chicken off to a lab to be tested for avian viruses to determine which it is.
After...
Those sure look like leucosis tumors I've seen on my home necropsies. Age is about right for death from the disease after being infected probably vertically. Was this little chicken hatched within your flock?