[COLOR=4B0082]Ok now my question is mareks something that spreads? because if that's what mine has I put her in the sun in a dog cage she happy falls over but cleans her self eats drinks an poops!! so do I have to kill her if I am willing to give her the extra care she needs??[/COLOR]
Marek's is probably one of the most contagious common diseases of chickens. Hence the fact it's present in as many as 95% of backyard flocks in some locales. It generally spreads on feather dander and in bodily fluids. If one bird in the flock comes down with symptoms, the rest of the flock has been exposed.
The ability of a bird to recover from Marek's varies vastly by individual situation. It's dependent on the strain of Marek's, the individual bird, their immunity to it, and various environmental factors. In my experience birds with paralysis but no tumors tend to have about 50% recovery. Birds who have both paralysis and tumors have a lot lower chance. Also, severity of paralysis seems to relate to recovery. The worse the paralysis, the lower the chance of the bird regaining function.
So is there anything you can do to treat the ones with no signs? ? Do regular chickens get this?? If thats wjat it is??
There is no treatment for Marek's, no. Some people claim to have had luck with Saint Johns Wort, which is said to have antiviral properties, but this is just anecdotal. Either a bird will recover on its own or it will not. Any chicken can get Marek's, again it's dependent on factors such as the strain of Marek's and the individual's immunity to it (as well as whether or not the bird was vaccinated - although mind that the vaccine does not prevent the bird from GETTING Marek's, just from showing symptoms of if).
Here's an excellent resource for learning about Marek's Disease:
https://www.backyardchickens.com/a/the-great-big-giant-mareks-disease-faq
There are a few other conditions that can cause similar symptoms similar to Marek's (vitamin deficiencies, consuming moldy/off food, and even injury as it can appear to be paralysis) so you should consider those options as being potentially your issue as well; since Marek's has no effective treatments it may be wise to pursue simple treatments for these issues to cover all your bases (e.g. starting the bird on a vitamin supplement to rule out vitamin deficiencies).