Marek's disease

[ValCoo]

What causes Marek's disease. Is there any way that it could possible be caused by the worming treatments given to chickens? They are such small creatures to cope with such a "poison"

 

[sumi]

Marek’s Disease is caused by 6 different herpes viruses. The virus concentrates in feather follicles and is shed in dander. Marek’s is highly contagious and spreads by bird-to-bird contact, by contact with infected dust and dander, and by darkling beetles and mealworms that live in the chicken house (although the virus has no affect on the beetles or mealworms).

 

[toritori]

I have had one chicken die today, a BYC suggested it might have been Marek's. What should I be looking for in the rest of the flock as far as symptoms?

 

[Nambroth]

I have had one chicken die today, a BYC suggested it might have been Marek's. What should I be looking for in the rest of the flock as far as symptoms?

Symptoms vary widely, and some can look like other diseases, while other diseases can look like Marek's. I know that's frustrating!

Marek's is a herpesvirus, but is not communicable to humans. It is highly contagious within chickens, though vaccination and genetic resistance can improve the chances that a chicken will not succumb.

Marek's can show up in different ways, depending on the chicken's resistance and the strain.

Classical Marek's often shows up via paralysis of one or both legs, and sometimes the wings. The typical pose is one leg forward and one back, however this is not always the case and it may simply show up as the chicken's inability to stand or walk. In the visceral form, the bird usually develops lymphomas or tumors on major organs, which often leads to death within a week. Sometimes birds with lymphomas may have trouble breathing, may go off their feed and water, may seem to try to eat but cannot "connect" with the food, and/or may have stools that are bright green and loose. Note that these symptoms alone do not mean that the bird has Marek's-- these are just symptoms that might be part of a diagnosis overall. Unfortunately once the lymphomas have formed, the outcome is usually death. There is no cure.

Classical Marek's (the above) usually shows in chickens that are under 1 year of age, but depending on when the bird is exposed to the virus, may also show later in life (though it is less common).

Ocular Marek's often shows up in older birds that are fighting infection, but it CAN show up in young birds as well. The iris may become discolored (often pale.. grey or blue) and/or the pupil may seem to "bleed" or change shape.

Cutaneous Marek's is the one I have seen the least often here on BYC but it is possible. It causes lesions and growths at and around the feather follicles, in the skin.

Birds that have been exposed to Marek's that have not developed a full immunity are often left with a suppressed immune system, meaning that while they may or may not demonstrate any of the above symptoms, their bodies are less able to fight off common disease vectors in their environment. It is why people who have Marek's positive flocks often have problems with Coccidosis and other diseases that a chicken's body normally would have less trouble fighting off.


I know that not everyone can afford it, but if you are able to and you suspect Marek's, you can consider having a blood test done. This can be done without culling the bird, as the blood can be safely drawn from a live bird. Texas A&M offers this diagnostic testing for Marek's: http://tvmdl.tamu.edu/tests_service...sease-(PCR)&unit_id=1187&unit_effdt=02-JUN-10
For some, it is not worth it, but for others it is worthwhile to determine if Marek's is in a flock or not, because it may make all the difference for people that wish to sell birds (which cannot be responsibly done if the flock carries Marek's).

 

[Wyandottes7]

X2. Marek's can really appear as almost anything.

 

[Brethren49619]

I had a pullet die a few weeks back. Now another is not doing well. The symptoms are different this time. Easier to show than explain, but our slow internet connection says it will take 4.5 hours for the video to upload. In the meantime,does anyone have video of early onset stages of Mareks they can show so that I can see a comparison to my situation?

 

[schnebbles]

I'm pretty sure I have it. My birds (2) started off with a bad foot, limping, and it finally got paralyzed. it's awful

 

[Sandstorm495]

For the sake of information for the future, does anyone know how the darkling beetles and meal-worms get the virus in the first place? And also, where does the virus originally come from before it is spread to a chicken?

 

[Brethren49619]

Brief video uploaded. Working on more video uploads. Darn slow internet

Can anyone tell if this is Marek's, or what it might be?

 

[toritori]

That definitely looks like my Paula Dean. I have read thte links from UNH and Cornell. The only thing that seems odd is that we only saw symptoms for 12 hours and she was dead that evening. How long have y'all seen symptoms? The other question I have is that all our girls are atleast 18 months old. Can I still vaccinate them now?