Not Mareks?!?!?!?! What could it have been?

[aligarysmom]

Ok did some reading. So you tested the blood of the chickens. But the study I read which defines leaky and was new to me, but extremely interesting , suggested that the viral load they are reading is from the feather shafts. Honestly I can see where that could mean blood is clean and skin is not. And that could be the reason for negative test. I would trust the test. PCR is pretty full proof as long as their controls are done and they don’t mix the samples up. You could call and request that if you sent new samples they run them again because something seems amiss mixing up patient samples can and does happen. Without any way to know they did it unless this happens and they retest. Ask if that’s an option

 

[aligarysmom]

Or do they test feather shafts. That would be the real kicker

 

[chickengeorgeto]

It is also my belief that the only way to confirm a Marek's disease diagnosis is by preforming a full Necropolis on a bird that has recently died from Marek's Disease. I would suspect any DNA test because there are at a minimum 7 separate strains or major varieties of Marek's viruses, each variety with its own DNA. There are even regional varieties of Marek's viruses. I suspect that each variety has its own unique DNA signature.

 

[April’s Zoo]

Thanks for the explanations and links.

I’m still trying to get my head around a vaccine that is meant to only blunt the bodies reaction to infection & not actually try to prevent it....
the closest thing I can think to compare it to is like when my son was vaccinated for chicken pox (lol) and got them anyway... To me, the severity of his outbreak looked the same as I would’ve expected if he’d never had the shot— but the doctor said that, without it, he would’ve had such a severe case that it may have ended up being life-threatening... so it was a good thing he’d been immunized.
So, the Marek’s vaccine is like that? They could still get the disease, but it will be less severe than if they’d never been immunized?

So, in that case, maybe it’s possible that the three hens you decided to test somehow have either a natural immunity or just haven’t had a long enough exposure to get infected yet?
Kinda like back in the day when moms would purposely expose their kids to chicken pox, but it seemed like there was always a couple kids who never caught it, even with multiple exposures....
I mean, there’s got to be some percentage of poultry that doesn’t get Marek’s, even though they’ve been exposed, right?.... otherwise, there’d be no point in them even doing the test— They’d just say that if you ever had confirmed Marek’s in any member of your flock, then all your chickens have it— period.

Another thought— What is the false positive rate for the postmortem testing? Maybe that’s where the fault lies? Depending on what the false positive rate is, I could see it being possible that the ones that died never really had Marek’s..... it would be improbable perhaps, but it still could be statistically possible.....

I think your next step should be calling the lab that did the PCR testing to ask them what they think the results mean, given the history of your flock. And I think I’d also call the lab that did the necropsies and associated testing, to ask about the false positive rates, and also see if they have any thoughts on all this....

Good luck. I hope you’ll update this thread with anything you find out....


Amusing tangent: {I remember a family down the street from me growing up, whose mom kept trying to give them chicken pox because she wanted all 3 kids to get it at once and in her words, “get it over with” .... problem is, they never got infected.... she must’ve exposed them at least a half a dozen times a year... I knew these kids thru high school, and they never did get the pox. It was sort of a neighborhood legend. As a matter of fact, I still remember their mom saying something to my mom about how she was afraid her boys would get them as adults, and then they’d never be able to have kids— so I asked my mom if it was really true that a boy couldn’t “make babies” unless they got chicken pox as kids— *that* was quite the “birds and bees” convo with my mother. }

 

[Kiki]

Hi all,

So this is an odd result I received yesterday on some blood tests I had done on my flock. This is not an emergency, I have no sick birds but I want to get your opinion/experience in what this could have been.

I had what I thought was Marek's disease take my whole flock over the period of a few months From October 2016- Feb 2017. I thought it was Marek's because the symptoms matched and the 2 Necropsies I had done by the CA Animal Health & Food Safety Office confirmed it was Marek's. Just this week, 5 blood tests I sent to a lab in Texas that performed Real-Time Quantitative PCR DNA testing for Marek's came back completely negative. WHAT THE HECK?!?!?!?! I'm SOOOOO confused. Here's the timeline and events, with necropsy documents and lab test results:

In October, 2016 2 of my 3 pullets died over the course of 15 days. The vet suspected Marek's and I sent one of the pullets (Fleur) off for a necropsy. It came back as death due to Marek's. None of my 3 birds were vaccinated. I've attached the necropsy for Fleur at the bottom of post.

A week later, when my remaining pullet (Mabel) showed no symptoms, I bought 3 new pullets from a local farm. The 3 pullets were vaccinated and the same age as Mabel, who had just lost her flock. I had hoped Mabel was immune. She wasn't. In February of 2017 (4 months later), she also died. Her symptoms started suddenly and she declined quickly. I had the vet euthanize her and sent her for a necropsy. It came back Marek's again. I've attached Mabel's necropsy

So at this point, I had active Marek's and 3 vaccinated pullets who had been exposed to Mabel and the environment.

In June of 2017 (4 months after Mabel died) I picked up 5 baby chicks. I brooded them in the house for about 10 weeks and had SUPER strict PITA bio-security in the house so that their Marek's Vaccine had time to develop resistance.

Since Mabel died, I haven't had any chicken losses due to disease or otherwise. I did raise some meat birds at the end of Summer in 2017 and I remember thinking it was strange that their organs were perfect, being exposed to Marek's and all. I processed them at around 12 weeks old which would have been time enough to develop visible tumors.

So, last week I sent off blood samples from 5 of my 7 hens to a lab in Texas that does DNA gender identification and real-time quantitative PCR testing for many diseases. I had them test for Marek's and my expectation was for them to tell me how virulent the Marek's I have here is, and how big of a virus load my birds have.

ALL FIVE BLOOD TESTS CAME BACK NEGATIVE FOR MAREK'S!!!!!!! WHAT THE HELL?!? I was absolutely floored! This makes ZERO sense! I live in an arid climate, so... no ground freezing and no moisture saturation to eliminate Marek's but even if that weren't the case, I have had CONSTANT chickens on site through the suspected Marek's outbreak! I've thought about it from every direction and can't for the life of me figure out how my flock is Marek's- free. Even if the 3 pullets I got to keep Mabel company were immune, there were only 6 months that passed between Mabel dying and my baby chicks being allowed outside which is not enough time for Marek's to go away. I've attached the lab results at the bottom of post.

Can someone help me make sense of this?!? I have a call into CAHFS and the lab is re-running the blood tests for Lymphoid Leukosis, although I highly doubt that was what was going on, because again... I've had no more losses. This is the most baffling thing!

Did your birds ever end up showing signs of Marek's
The ones you have this test done on?

 

[joycee]

I would love to know the outcome of this mystery. Is there anyone out there still? Don't leave us hanging!