No I was suggesting foods high in selenium rather than giving it as a supplement. Seafood, fish, wholemeal bread, sunflower seeds and eggs... these all contain above average levels of it I believe and are things that a chicken will probably enjoy eating.
I tried turmeric and black pepper mixed into scrambled egg but after a week they got sick of the turmeric and I decided it was better that they eat and enoy their food than that I try to get something into them that they didn't like. I also ferment feed which I think benefits birds which may have digestive problems and Marek's can cause this.
My view is that the flock has already been exposed and the sick bird will be happier and therefore have a better chance of fighting the disease by remaining with the flock but in a safe and supported environment. I have an old sideboard that I converted into a brooder/infirmary and I have that inside the hen house. I had a bird (Hope) so badly lame last winter that she had to be propped up in a nest in there as she was no longer able to stand or go out with the flock. I had given her till the weekend and then I had decided to cull her as she had been like this for several weeks and had started to lose her appetite and the will to live. In between times another lame one (Hoppity) started to struggle within the flock and I put her into the infirmary too. I was horrified to see them fight despite their disabilities. There were a couple of horrible dust ups but after that they became firm friends and encouraged each other. The really bad one, Hope, started to show slight signs of improvement and I kept postponing the moment of truth. We got some fine weather in early spring and I was able to put them out in the sunshine on the grass in a cage and scatter scratch about for them and the rest of the flock. Hoppity didn't get any better physically but gained confidence and strength. She was already quite agile though and able to support her slight weight quite easily on just one leg as she was very petite and just hopped about everywhere. Hope became able to waddle using her wings and then limp and eventually half run/half fly. After several months, I was able to let them loose to free range with the flock (I have a large mixed flock) and they even started laying eggs and could get up onto the roosts at night with the others.
I can't tell you how much pleasure I got from those two birds. We became so close during those months of caring.. Sadly I had a fox attack a few months ago and was devastated that they were amongst the six victims.
Other people will have different views and some strains of Marek's are milder than others, so I am only able to give advice based on my own experience. Thankfully I have a mild strain, so I have found that supportive care and diet can help I was lucky with these two birds that they were sick at the same time and I am certain that having companionship in the infirmary was what turned the tide for the really sick one. Unfortunately that is not something that you can arrange but just a fortuitous occurrence for these birds but it made me realise that completely isolating the bird from the flock is detrimental to it with this disease and even if it makes a recovery, the stress of reuniting it with the flock is likely to trigger another attack. I would rather keep the sick bird in contact with the flock as much as possible and of course, risk increased exposure than isolate the bird.
As I said before, it may not be Marek's but all of the dietary suggestions above will not harm it to try. Marek's is a very serious and often fatal disease though, so if the worst happens it is beneficial to have it confirmed by sending the bird off for necropsy or at least doing a post mortem examination on it yourself if you feel able.
There are several very informative threads on this site regarding Marek's and peoples' experiences with it and I would recommend you read some of those as I have only been dealing with it for a year and gained a lot of my info from reading them.
Good luck with it and I'm here if you have any other questions or need support.
Edited by rebrascora - 11/15/15 at 2:08am