- Apr 28, 2011
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Mareks is a viral infection in the Herpesvirus family. These viruses target the nerves. It takes at least 3-4 weeks after infection for lesions to start showing up. Early-affected birds may show paralysis, or may just act sick and die; some may not show signs and recover. If the initial infection does not cause death, the virus settles in the nervous tissues and can show up later (many herpesviruses cause latent (inapparent) infections that reoccur later - think chickenpox/shingles, or herpes simplex/skin lesions). These are the older ones that develop tumors of the nervous system; they develop progressive paralysis and eventually die. So healthy birds can carry and shed the virus without themselves showing illness.
The virus is spread in dander from feather follicles and inhaled.
Vaccination is with a similar strain of Turkey herpesvirus that itself does not cause illness. For it to be most effective, is needs to be given in the first days of life. (Vaccination will not prevent infection, only disease - so vaccinated birds may still get the virus and pass it on to other, unvaccinated birds, although this is much less likely to happen).
There are different strains of virus, and some are more lethal than others.
Lady, as Dr. Fulton said, all of our flocks are likely exposed and eventually will be infected with Mareks. It is natural that some folks will feel uncomfortable regarding your flock, just as some avoid those with cancer or other serious diseases. It is good that you can share your experience here, and not everyone will feel that way about your birds.
