Marek's Disease. Questions, Questions, Questions...HELP!

[farm-gal91]

I recently had a run in with marek's in ONLY my seabright hens. How strange right? These hens were said to be vaccinated when chicks. They were all at least 6 months of age when they started showing clinical signs. Isn't that a little old? They have all passed (humanely euthanized) because I could not bare seeing them like that anymore. I have one that we may open up tomorrow at work and I am curious to see the lymphoma tumors inside her. Anyone else curious?
I am so distraught over this and confused at the same time. I have read so many articles on Marek's and it seems it usually only affects the younger guys and vaccination helps. Are bantams more susceptible to the disease? Has anyone else dealt with this? Is anyone curious to see photos?

 

[TweeTea]

I just posted on Mareks in the following thread

https://www.backyardchickens.com/t/730135/advice-for-sick-chicken-please

It is very frustrating but as I understand it, young chicks are susceptible to contracting Mareks but it can take up to 18 months for it to develop to the point of killing the chicken. Mine dies at about 10 months old.

You might find that only one group of your chickens were affected because they contracted it from the location they were hatched before comming to your flock, differences in the age of your flock etc.

The vaccination is expensive so I think they apply it (a spray) to the chicks all squished together in a confined space. This means that any chicks pushed down don't get vaccinated. This is also what I had with my girl. It is odd though that you had so many supposedly vaccinated chicks contract it. It may indicate a very poor approach by the hatchery, using too little spray in an effort to save money.

 

[farm-gal91]

Thanks for the info, I will read your link next. I'm worried months or years from now that my good hens will start showing the clinical signs. They are mature hens but still.....frustrating. I didn't know it was a mist, I always thought it was an actual vaccine given in the muscle, but then again, what hatchery would go thought thousands of chicks and vaccinate them like that.....my high hopes.

 

[farm-gal91]

Great post! Very informative.

 

[TweeTea]

Pretty sure most hatcheries use a spray. I looked into buying some but it was too costly for my tiny flock.

I also read quite a few scientific research articles on the transmission of Mareks and how it alters with the age of the hen. If your girls are over 12 months there is a good chance they are unafflicted, if they are over 18 months there is a very good chance they are clear and older than that I would completely throw the worry out the window.

 

[centrarchid]

Which birds are infected can be a function of genetics for both birds and virus. With respect to whether vaccine works or not, that can be a function of the viral genetics. I have tangels with Mareks two years in a row and kept birds only mildly affected long-term. From now on, even mildly effected birds will be euthanized since complications arose in most. Even though most birds were directly exposed to sick birds, the version of mareks I have be having does not seem to spread easily from those birds and no mareks has been noted this year. For me it is a fall season disease.

 

[TweeTea]

Which birds are infected can be a function of genetics for both birds and virus. With respect to whether vaccine works or not, that can be a function of the viral genetics. I have tangels with Mareks two years in a row and kept birds only mildly affected long-term. From now on, even mildly effected birds will be euthanized since complications arose in most. Even though most birds were directly exposed to sick birds, the version of mareks I have be having does not seem to spread easily from those birds and no mareks has been noted this year. For me it is a fall season disease.

That is good to Know! I never found any reference material that gave a good discussion on how Mareks susceptibility might vary according to breed / genetics, only that it would not transfer to other birds (non-chickens).

I would assume it is more closely linked to the genes of the chicken than the genes in the virus. As the nature of a virus is to continuously mutate and change over short time periods. So I would assume it is more likely that certain breed have greater or lesser immune responses to this type of virus. I'd be keen to hear which breeds have been unaffected.

 

[farm-gal91]

Good grief I hate this virus! I feel doomed with it and my seabrights were my favorite! All of the ones that dies were of the same flock from poultry hollow hatchery ( will not be using them again since every bird is sickly besides marek's and many other people have complaints. Conditions are filthy, people are not knowledgeable). I have one seabright left but she is well over 1 year old and very healthy, she is my favorite and always follows me around, perches on me, lays the most, and I am so worried one day I will go to the coop and find her with it.
I will be doing a complete coop cleaning and completely remove all bedding, and spray everything with Clorox. Whether this helps or not I don't know.
I guess when I want to get more chicks I will see if they are actually vaccinated or just sprayed. Thank you both for your information, this was very helpful.

 

[centrarchid]

That is good to Know! I never found any reference material that gave a good discussion on how Mareks susceptibility might vary according to breed / genetics, only that it would not transfer to other birds (non-chickens).

I would assume it is more closely linked to the genes of the chicken than the genes in the virus. As the nature of a virus is to continuously mutate and change over short time periods. So I would assume it is more likely that certain breed have greater or lesser immune responses to this type of virus. I'd be keen to hear which breeds have been unaffected.

My American Dominiques appear not to be affected while the American Games got hit relatively hard. Out of 80 birds, 3 where affected in first year and 5 the second year. No birds alive in previous year where affected in second year. Flocks were mixed or at least coming into direct contact at waterers. I think migratory wild birds are source of infection since outbreaks among my birds occur when large number of warblers and other songbirds are flying through at night. Some of those die and chickens eat them. Where we used to keep our American Games about 300 miles to east Mareks did not appear to affect them or birds where culled wilthout knowing Mareks may have been a potential health issue. All American Dominiques I have now are from Missouri where I presently reside.

 

[farm-gal91]

How interesting. Has anyone had a necropsy done on any of the deceased birds?