what is Mareks disease

[animalwild]

I think one of my chickens has mareks , but i don't know what it is or how to treat it. So would someone be kind enough to tell me what Mareks is please.

 

[Sarah42]

Mareks is not treatable as well as fatal. It is a disease that generally affects young birds (8-20 weeks) but has the ability to kill mature adults as well. It is a highly contagious viral neoplastic (or you can just think of it as viral) disease that affects the T-Lymphocytes. There are many types of Mareks Disease, but the most common ones are Classical and Acute. Symptoms include:

-Paralysis of one or multiple limbs
-Dilation of the crop
-Difficulty breathing
-Tumors within the internal organs

The best way to deal with a bird that has Mareks is to cull it from the flock. I believe there are tests that a vet can do to confirm Mareks, but that may be a little expensive. Another thing you could do to prevent Mareks in the flock is to have them vaccinated. Most, if not all, hatcheries will vaccinate, but some need to be asked to vaccinate while you're ordering your chicks. Good luck with your bird.

 

[Eggcessive]

Can you describe some of your chickens' symptoms? Here are some very good links to read about Mareks:http://extension.unh.edu/resources/files/Resource000791_Rep813.pdf
https://www.backyardchickens.com/a/the-great-big-giant-mareks-disease-faq
http://partnersah.vet.cornell.edu/avian-atlas/#/disease/Marek's_Disease

 

[rebrascora]

Marek's disease is caused by a virus which is spread via dander dust which infects the bird with the virus when inhaled. It is very contagious although not all birds that are infected will get symptoms, so they can look perfectly healthy and still be spreading the disease as carriers. It's therefore pretty common.
It is a disease which can have many different symptoms which is why it can be confusing and difficult to diagnose. Also the symptoms can appear and then disappear, but may reoccur later and often more aggressively. It usually affects the nervous system and lameness is one of the commonest signs. Some strains of the virus affect the eyes and the pupils become enlarged and distorted instead of round and appear hazy. Tumours can develop on the visceral organs as well as the skin and muscle tissue. Wryneck can also be a symptom. Weight loss and under development despite apparently eating well is another sign.. It usually affects juvenile birds but can develop in older chickens. I believe pullets are more prone to it than cockerels. Stress can trigger an outbreak or make the symptoms worse.

Lameness was a key factor in my flock. I had 3 young birds go lame in a matter of 2 weeks and then another 2 a few weeks later. They walked down on their hock on one leg, like it was dislocated. Some got better on their own, 1 has learned to hop and holds the other leg up with the foot clenched out of the way and has been like that for several months. She looks the picture of health apart from her leg.... beautiful plumage, bright red comb and bright alert eyes, but she is only about half the size she should be. One sadly had to be culled as both legs became paralysed and she kept rolling onto her side and couldn't get up and then she developed wryneck as well..... she had huge tumours in the muscle tissue of her leg and abdomen when I did a post mortem.

Off the top of my head that's a short recap of what I've learned over the past 4 months since I started seeing lameness in my flock and doing research. What makes you think your chicken has it?

 

[animalwild]

Another question I started about one of my chickens eyes she said it could be possibly marked disease and so I was wondering because this is the longest I have ever had my chickens so I'm being a bit more cautious now.

 

[CAmountaingirl]

After reading all the posts abt Marek's is looks as if we have it too. I have a hen in the living-room that cannot walk but is eating. 2 yrs ago she seemed to have a respiratory problem and after she recovered she went blind in one eye. Now she can;t walk. Her sister died a month ago, we just found her dead in the chicken house one morning, no symptoms. Several people on here said to feed polyvison but the universities said they will certainly die plus it is contagious. What to do?

 

[Eggcessive]

After reading all the posts abt Marek's is looks as if we have it too. I have a hen in the living-room that cannot walk but is eating. 2 yrs ago she seemed to have a respiratory problem and after she recovered she went blind in one eye. Now she can;t walk. Her sister died a month ago, we just found her dead in the chicken house one morning, no symptoms. Several people on here said to feed polyvison but the universities said they will certainly die plus it is contagious. What to do?

You could be dealing with something else besides Mareks. I would look at a couple of links here, and if you lose her, you may want to get a necropsy performed by your state vet. In hens her age she could have other problems, such as egg yolk peritonitis. Mareks can cause blindness, lameness or paralysis of one or both legs or wings, and tumors anywhere in the body. But it could be other things too. Mareks usually affects chicken that are young, or if exposed to a new addition to the flock, an older chicken can be exposed and symptoms can show up in 3 or more weeks. Here is some info about Mareks, and a link for state vets in the US:
http://www.usaha.org/Portals/6/StateAnimalHealthOfficials.pdf
https://www.backyardchickens.com/a/the-great-big-giant-mareks-disease-faq