Ok. Having a bit of a problem, I suspect the recent 2 deaths from a separate flock I have had were due to Marek's disease, they both got very ill and passed away. I have also got one paralysed Silkie, who 'behaves fine' and eats well but clearly cannot walk. Should I put her down? I know she is a pullet and is targeted, and I really like that chicken. But, it could infect the entire flock and I do not want to lose them all. I disinfected their pens before her arrival, how come she has come down with a disease!
What should I do?
Also, I have some important questions on medication:
1) How can I vaccinate my chicks from Marek's and other disease without injection? Does medicated feed work well for them?
2) Should I buy vitamins and 'pick-me-ups'? I have had ill chickens from time to time but do they work?
3) How can I disinfect the pens from disease?
Thanks for any answers, having a bit of a stressful time at the moment.

Also, I have some important questions on medication:
1) How can I vaccinate my chicks from Marek's and other disease without injection? Does medicated feed work well for them?
2) Should I buy vitamins and 'pick-me-ups'? I have had ill chickens from time to time but do they work?
3) How can I disinfect the pens from disease?
Thanks for any answers, having a bit of a stressful time at the moment.