Have you checked for worms in case thats the issue?
Yes you can, there is ancedotal evidence that it minimizes tumors. I did that with my flock and any incoming no matter the age. My oldest mareks positive was a 16 year old silkie, my losses to mareks dropped significantly. You can get the...
Old post, but dont always assume mareks, get fecals done, check for mites and start vitamins. My flock is positive and i vac any incoming since there is ancedotal evidence that it limits tumor grown. My deaths have dropped considerably. Check here for live testing...
Well I wouldn't recommend a metal shed, yes I've never had predators other than snakes, but oklahoma summers make it an oven. So you'd need a way to cool it.