Can adult chickens get mareks?

[adcockfarm]

hi we have a 7 hen flock, and one has been recently diagnosed with mareks.

here is the post about her: https://www.backyardchickens.com/t/1164907/is-this-mareks-and-what-should-i-do-help

we have to keep them in a garage because of noise. we moved the sick chick outside.

here are the ages:

(sick) 2 mo 1 wk buff orpington
(healthy) 1 mo 1 wk black australorp
(healthy) 2 mo 3 wk white leghorn
(healthy) 3 mo 2 wk barred rock
(healthy) 3 yr blue wynadotte
(healthy) 3 yr welsummer
(healthy) 3 yr americana


are the older ones immune?
what should i do to protect the flock?
is the buff orp dead for sure?
would it help to get rid of the buff orp?
if we got a new buff orp would it be at risk because the pathogen is in the air and dirt?
help!

 

[Eggcessive]

Have you tried chick vitamins on your pullet with the leg problem? Riboflavin deficiency can cause walking or sitting on hocks, and curled toe paralysis, and if treated promptly, it may help. I would definitely try the riboflavin and try to get her to eat and drink.Older chickens are not immune to Mareks, but it tends to affect younger chickens. If you bring a carrier into the flock, it is possible to see symptoms after 3 weeks of exposure. You cannot really say for sure that you have Mareks unless you get a diagnosis through a necropsy. There are many things that look alike. A affected chicken needs to be sent to the state vet or college poultry lab for a necropsy to do testing for Mareks. In California, it is low cost. If there has been a positive case of Mareks, it is infectious by the dust and feather dander form the chicken, and may last years in the environment. All chickens should be considered carriers at that point. Any that have not been vaccinated will be at risk. Here is some info about necropsy:
https://www.backyardchickens.com/t/799747/how-to-send-a-bird-for-a-necropsy-pictures
https://www.backyardchickens.com/a/the-great-big-giant-mareks-disease-faq

 

[adcockfarm]

so are my other chickens infected? they were in a coop inside their coop for the purpose of integrating them when they were older... and they were outside in a pen because they were small, and we let the big ones inside that pen when they weren't around one time so... the sick chicken has been outside separated the other ones are inside but I'm concerned because it is dusty in their coop so i might clean it today if i have time. thanks

 

[Eggcessive]

If there is Mareks, it would have already exposed everyone by the dust and dander. It's impossible to clean or disinfect. The farther away the better. I would get the necropsy if the chick doesn't respond to the vitamins within 2 weeks, but I really would try the riboflavin since deficiency is fairly common. It is very similar to some Mareks symptoms.