Moving Forward- Breeding for Resistance to Marek's Disease

[gjensen]

LOL. That's all you're going to get about Marek's , likely, commonly, could be, consistent with, chances , does not look like............... the more we know about Marek's the more we don't know. I've read there's 3 parts to the testing. 1- examination for tumors. 2. examination of tissue microscopically. 3. a PCR. Not necessarily in that order . A lab will say positive or negative for tumors, enlarged nerves or a PCR. Based on that information, a vet at a disease lab would base his answer accordingly.

I've had 2 negative now. But they were not symptomatic of Marek's.

George, quote: Once a young bird is @ the 20wk range it is not likely to succumb to the disease whereby it could be introduced to the main flock or adjacent facilities.

Good thing you said "not likely", because I've had some up to 8 months old, and my first was 18 months old and had every classic symptom.

Within the last 2 days my BR Fern has succumbed to paralysis. Today she can't even hold herself upright with her wings. She's 5 years old. I'll be sending her out for a necropsy and it will be the first one I"m sending that's actually symptomatic..

A few years back, I had 3 chicks from different sources. At 4 months old, they were put out with the flock. A month later, one started to waste and died. One other wasted and died at 8 months old. I didn't know I had Marek's at the time. The rooster lasted almost 1.5 yr old, when I noticed his pupils had an odd shape to them. He wasted away and died. One hatched by me, one egg hatched that was laid in my car, and one chick from a friend.

There are no rules or solid symptoms.

I should have also included the word as for "not as likely". The idea should lower the incidence rate. I had wondered if this method coupled with vaccination would eliminate the majority of the problems. Sometimes these things are a series of smaller victories.

I agree on the rules. I have been listening to the claims on how they would have the Ebola situation under control if it ended up here. Now that it is here, we will see how much they have it under control.

 

[luckysaysgo]

I'm really new to chickens and am perhaps misinformed but I thought that there were several strains of mareks any of which could be present in the dirt itself and that in addition wild birds could have it..and I thought that a bird could be resistant to one strain and not others..so as a newbie if I am getting a basic understanding it would seem that mareks isn't something we can deal with by culling because, well, it's in the dirt? And dirt is..everywhere do wouldn't logic say to breed for resistance? I'm not trying to offend. I am simply here to learn and see if I am understanding the facts. And I'm really sorry to those of you who have lost birds.

 

[seminolewind]

Is there an antibody titer test for Marek's?
Is the virus shed when it's dormant.
Is using plasma (instead of vax) a possibility in chickens? What route? Is oral acceptable?
Will there be a problem using plasma with "original sin"

Trident, tried to copy as much as thought pertinent.

 

[seminolewind]

I'm really new to chickens and am perhaps misinformed but I thought that there were several strains of mareks any of which could be present in the dirt itself and that in addition wild birds could have it..and I thought that a bird could be resistant to one strain and not others..so as a newbie if I am getting a basic understanding it would seem that mareks isn't something we can deal with by culling because, well, it's in the dirt? And dirt is..everywhere do wouldn't logic say to breed for resistance? I'm not trying to offend. I am simply here to learn and see if I am understanding the facts. And I'm really sorry to those of you who have lost birds.

Hi and welcome! First off click on "Marek's the big FAQ" link at the bottom of my posts. It should help you understand it better. It would take me too long, LOL.

If you buy hatchery chicks, and request vaccination, the vaccine they use is a 3 in 1 which is better than we can get. To get Marek's , your chicken must have contact with another chicken that has it. Once they have it, it spreads quickly and the chickens spread the virus in their dander. It does not randomly live in the ground unless Marek's virus chickens lived there. Wild birds can spread it, but it's uncommon. The wild bird would have to hang out with one flock, then fly to your flock and hang out. I don't know how big a territory is for a wild bird.

 

[seminolewind]

I want to say something the censor will catch.

I'm so sorry about your Fern.

I think we all know that the ones we have saved or made better become closer to our heart. Fern came from the next door neighbor. He came to the door with her and she had a broken leg. I told him there's nothing I could do. He went home and put her back in the coop!!! I got her and said I'd try. Of course after 6 weeks of her hanging in a sling on my patio, I wasn't giving her back. So I told him she was too delicate for his big rooster and I would find him a nice big hen, which I did.

I have given him chickens over the years, and a few chicks. They all live happy next door. Which makes me think that his had less concentration to their exposure. Gosh there are so many factors involved with resistance , I'd go crazy. I'll just vaccinate.

 

[Nambroth]

Thank you for your answer. I still haven't had anyone really address my question so I wonder if I'm not making myself clear. I'm sorry if I'm not. When they say it's "likely" Marek's, that does not sound as if they've put the tissue of a tumor or whatever on a slide, added some agent that turns some color (only example I could think of) and saw something that says, "YES, this color indicates the Marek's virus in this tissue!" Do they do that or is it only visual? Considering that there are several diseases that can cause weird livers and cancers other than MD. Gatherings of odd cell growths are not always cancerous, either.

Do you see what I'm saying? Though the virus may be common, it seems that folks jump to the MD conclusion so quickly when other things can mimic MD. A bird limps and someone screams, "Mareks!" when all it did was sprain its leg.

I did read all of Jennifer's FAQ so part of what I'm asking sort of was prompted by that long read. I know my birds are MG/MS free, which everyone says is near to impossible, but those tests seem more definitive than the ones for MD, they are not visual observations. All of this reading is making me feel hopeless and then, when I see supposedly respected breeders selling and showing birds from their MD-positive flocks, that makes me insanely angry, to think they are helping to cause all this heartache we are seeing on this thread and others. I'm going to have to find a way to feel about this, a philosophy about it, so I can stop obsessing over it. I don't feel as if I'm helping here.

Oh boy, finding a way to feel about this has been a journey I've been on for two years now. Every time I think I understand something, another paper or idea comes along that makes me more confused than ever. I couldn't find a concise website with ANSWERS in one location so I started to make one myself. It took a year to get it to where it is today. A year of researching at least once a week, sometimes more often. And it's still confusing, and maybe wrong in places, but I am doing the best I can. I have to laugh a little, or I would cry....

When an avian examiner looks at a bird post-mortem to determine cause of death, they take into consideration symptoms shown in life, and gross necropsy results. Gross necropsy is what you and I can do at home; carefully open the bird and do a visual exam. Now, avian examiners, such as those at state labs and well-educated avian vets, etc, know the very subtle tell-tale symptoms of various diseases by sight. So-- most of the time, the symptoms are considered, the bird is opened up, examined visually, and a 'best guess' is taken. If any given disease is suspected, only then are further tests sometimes run (for example if bird symptoms are respiratory and upon exam MG/MS is suspect, most labs will test for it since it is, as you mentioned, a pretty clear cut test). However, testing is up to the examiner, and/or up to the client (you, me, the next chicken keeper) to request. Some labs will test suspicious tumor tissues/nervous tissues of Marek's is suspect, and some will not unless the customer requests it.
Unless the necropsy report specifies that specific tests were done (such as PCR), then one must assume it was visual only.

Though other testing is available, I have personally not seen any lab or vet test for Marek's in any way other than the following:
- Visual necropsy
- Examination of the sciatic and sometimes vagus nerve (looking at samples of the nerve under a microscope for lesions, which are not always present or even visible!)
- PCR testing.

Has anyone else here ever had any of the other testing done on their bird? Do any of the labs still do cultured tests at all?
I see from Karen's scans that titration testing has been done in the past. Has anyone ever had this test done on a bird by a lab??
I am just a layperson so maybe these are stupid questions, but I really haven't read or seen these done in the last few years that I've been researching this...

It is worth mentioning a few things:
1) A lot of people do jump at "OMG it's Marek's" without any sort of professional exam of a deceased bird. It's one reason why the "Marek's look-alikes" part of my FAQ is so darned long (and could be longer...)
2) Some of us here have had birds tested that became ill after we had a Marek's confirmed case in our flock. We were sure it was Marek's. Then the tests were negative. This could be for two reasons-- a) The bird had a look-alike disease, and/or b) false negatives.
3) Despite all this, Marek's is pretty common. But as it has been so aptly put... it's like chasing a ghost. Is it Marek's? Is it not? Nothing about this is straight forward other than a few base facts.

 

[Northie]

I rather like this entire discussion. Very lively and civil, too. A nice change from some on here, right?

Agreed

 

[gjensen]

I'm really new to chickens and am perhaps misinformed but I thought that there were several strains of mareks any of which could be present in the dirt itself and that in addition wild birds could have it..and I thought that a bird could be resistant to one strain and not others..so as a newbie if I am getting a basic understanding it would seem that mareks isn't something we can deal with by culling because, well, it's in the dirt? And dirt is..everywhere do wouldn't logic say to breed for resistance? I'm not trying to offend. I am simply here to learn and see if I am understanding the facts. And I'm really sorry to those of you who have lost birds.

Like others have said, it is spread by the dander. Still once a poultry yard has it, it has it. That is where people get or say that it is in the ground.

Wild birds certainly carry it, and you could say a more original cause. It is just not as likely of a source unless you have a flock of starlings hanging out with you, or a bird feeder in your poultry yard. Level of exposure matters.

There are different strains. Some more virulent than others. Like all pathogens they are constantly evolving, and not uniformly. The most effective vaccine now, may not be 25 or 50years from now.

I think that if you are breeding, you should certainly "breed for resistance" and manage it as effectively as possible without vaccinations. That is unless you start suffering heavy losses. Then you have to decide what is most important. I will not vaccinate my birds until I have to. This is an opinion. I think that everyone has decide for themselves how they want to deal with it. We do what we do for different reasons.

 

[seminolewind]

All of this reading is making me feel hopeless and then, when I see supposedly respected breeders selling and showing birds from their MD-positive flocks, that makes me insanely angry, to think they are helping to cause all this heartache we are seeing on this thread and others. I'm going to have to find a way to feel about this, a philosophy about it, so I can stop obsessing over it. I don't feel as if I'm helping here. Quote speckledhen

Those people will be banned from the other side of Rainbow Bridge.

I know what you mean. It's hard to not obsess . Or not be angry. Bad things happen to animals all over the world. The abuse of helpless animals is unending.

Instead of causing myself depression-that I take lots of pills to prevent, I had to find a neutral ground in my mind. If I see something bad happening, I stop it. If someone needs help I help. The rest is to know that MY animals are well cared for and loved. I can control my own little Private Idaho (LOL). I stay home unless I go to see my horse or get feed. I spend hours in the back with all my chickens. Other people will have to live with themselves and their conscience. I will live with my conscience.

Cynthia, when I discovered Marek's, like others here, I became obsessed with learning and educating others. And being careful to listen rather than jump in and diagnose everything with Marek's. You really have to think about all your posts (65,000 or so) and how many have helped someone. How many people trust what you say. How many people you have made feel welcome. Your reputation has made you someone people listen to. Which is a great thing considering the subject of Marek's.

You have oh so unknowingly helped or saved many from anguish just by starting this thread. And I know what I'm talking about!

The thing that hurts me the most on BYC is when some new first time owner of chickens is just so full of joy and love for their chickens, then they start to lose them, and don't know why. They did everything right, they feed them well, their new coop cost them a small fortune. With Marek's, nothing compares with the devastation of losing chickens and the symptoms are so broad that it doesn't give you any clue as to what illness they have. Then there are those who give false hope because they have the Cure for Marek's.

Many many members are learning this Marek's stuff right along with you and save themselves a lot of pain. So maybe find some peace in who you are and the good you've done whether you're aware of it or not.

It's after midnight and I tend to get philosophical and type! Night.

 

[seminolewind]

Some more pages.