There a lot of myths and misunderstanding about Merek's --
Here is a member page I started some time ago (2012) -- asking for help from the BYc community -- so there are some really good contributors - both experientially and research-wise. --
Also -- although it is in the page -I'm putting a link to Nambroth's Merek's page.
Anyone who has something to contribute -- especially if it is research backed, please feel free to post -- but Please -- nothing that is boarderline -- for example -- not trying to hurt anyone's feelings -- but there are some approaches that actually introduce poisons to the chicken's system in the name of medications. The intention is NOT to start a medication discussion -- it is to ask that only fact-based (e.g. university researched) articles are attached.
Here is an example of a product that some tout that I would request NOT be attached.
although the above evaluations - such as the one from the Mayo clinic - are regarding human consumption -- I would expect it is NOT given to chickens -- and some promise the product as the 'cure' for Marek's --
One thing that is aggravating is finding that so many chickeneers get reports back on necropsies with cancerous growth but the report might say inconclusive it was Marek's or might be something else. Hate Marek's whatever it is!