Rooster with mass in neck, possible tumor, thymus response -- Marek's

[canesisters]

These might be on this thread already, but I stumbled across them and thought they would be useful to folks following on here.

Thanks to Seminolewind for gathering this info:
https://www.backyardchickens.com/a/mareks-virus-the-most-frequently-asked-questions

http://fowlfacts.proboards.com/index.cgi?board=afflictiondiseaseff&action=display&thread=1183

 

[Nambroth]

Nambroth-

I have ordered a mix of chicks that haven't arrived yet- some are laying breeds which I'll keep long-term, others are Cornish Xs which I'll only have for a few weeks. I plan on preodically ordering more Cornish X chicks which would be raised adjacent to the layer's pen.

Have you found anything in your research about whether or nor Mareck's vaccines are effective/beneficial for flock management in a situation like this?

I've asked the hatchery to vaccinate. (Since I can't choose only some, they all will be vaccinated). But I've been wondering about vaccinating future successive batches of Cornish Xs. Could they be exposed in the few weeks that they're alive and then pass it to the layers? Would it be ineffective to vaccinate them because their immune systems wouldn't be boosted before they go to freezer camp? Would it be unnecessary because they wouldn't be around long enough to pose a threat to the layers?

I hope this makes sense- I only had about 3 hours of sleep last night and am suffering for it.

I'd be greatful for any opinions you have.

I need to preface this with the fact that I am not an expert nor a vet, and in fact have only started researching Marek's in-depth just this month. So please do not take my advice over someone who knows more than I.
I also want to say that there is a risk in most things we can do with our birds... even people with totally closed flocks are not 100% safe, but they are much safer than those without closed flocks. I really think that educating oneself is the most powerful tool we have.

Here are my thoughts. You start your flock as day-old chicks that come from a hatchery, and they are vaccinated. This has a very low risk of introducing Marek's.
You butcher your meat birds, and keep your layers.
You then order more meat birds (as day old chicks, right?) from a hatchery and you are not sure if they should be vaccinated or not. Right?
I have a few thoughts on this based on my research.
1. The vaccine is remarkably inexpensive per chick; but...
2. You plan on butchering the cornishX birds at what age? Around 10 weeks? (I haven't raised meat birds so I don't know when they are typically processed). If so, Marek's can show up earlier than that... Depending on the strain, it often presents symptoms at 6-12 weeks old.
If you did not vaccinate your meat birds, and they came as day-old chicks direct from a hatchery (with no stop-overs such as feed stores or someone else's house) then your risk of introducing Marek's to your established birds is very low. If your meat birds (day old direct from hatchery chicks) come down with Marek's, it means it was already in the environment, and it wouldn't matter if you brought them in or not, because it was already present. Does that make sense?
If you have Marek's in your yard/pens/etc, for whatever reason (it came in from the environment, or from a new adult bird you brought in) then your vaccinated birds would likely not succumb to it (it's thought that there is a 80-90% protection rate), but the un-vaccinated meat birds might.

So, if it was me, and I was keeping a closed flock except for direct-from-hatchery day old chicks, I might not vaccinate the meat birds. If I ever intended to bring in birds from the outside that have the chance to carry Marek's, I would probably get them vaccinated, just so I didn't lose any before it came time to butcher them (this would be more of a financial loss than an emotional one if you plan on butchering anyhow). If your layers are vaccinated, and your meaties are direct from hatchery day-old chicks, your risk for introducing Marek's via your meaties is very low. Not zero, but very low.

If none of that makes sense please let me know!

Isn't it nice when you have one nearby? I never looked into a poultry vet and I was nervous I wouldn't be able to find one, but it turns out, my nearest poultry vet is only a half hour away! I hope to become an avian/reptile vet someday. How do vets not pass Marek's on to other birds or their own birds? They handle these birds all day, so wouldn't they have to worry about picking up diseases? That is my only concern.

There is a small risk, but any vet office worth their salt is informed about infectious and communicable disease, and cleans the exam room between patients. I was at my vet's office for quite a long while for the duration of Trouser's visit, and was invited to the back patient care area while I waited (I think the vet realized that I had an interest in avian medicine, and was showing me the various procedures she had done that day such as x-rays). They immediately laundered all towels used in patient exam, and they cleaned the floors and countertop with a disinfectant (and presumably virucide). However, you should never be afraid to ask your vet, and you should never feel it's rude to voice concerns about your animal's health.

 

[shadow rabbit10]

Thanks! Your knowledge and advice is well appreciated. And by the way, you say you're not an expert, but keep in mind, you had an experience with Marek's. Some people may know about Marek's, but never actually dealt with it. Knowledge is gained through experience.

 

[katbriar]

Nambroth- thanks for such a detailed and well worded reply. I had been looking for information and trying to inform myself BEFORE I became a chicken owner. Marek's is such a confusing disease. I had not realized how early symptoms could present themselves (and I'm sure birds would be shedding before they had noticible symptoms) and for me that succeptable window of time new meat chicks would be around my layers is enough.

Number of natural transmission routes (wild birds, who doesn't have them around?) + ease of transmission + ease and low expense of vaccination = one more chicken owner that will vaccinate

I've asked locally if Marek's is an issue. Most people have no idea what I'm talking about. But there are three feed stores shipping in hundreds of birds a week to be bought and managed by people that have never given it a second thought. I guess one of these days it will hit.

Canesisters- thanks for posting the helpful links. I was particularly impressed with the story of how Marek's went from being a problem for large operations to now mostly affecting backyard owners because of the husbandry practices. I had also forgotten about the week incubation for vaccinated chicks to develop immunity. Important point.

 

[Nambroth]

Nambroth- thanks for such a detailed and well worded reply. I had been looking for information and trying to inform myself BEFORE I became a chicken owner. Marek's is such a confusing disease. I had not realized how early symptoms could present themselves (and I'm sure birds would be shedding before they had noticible symptoms) and for me that succeptable window of time new meat chicks would be around my layers is enough.

Number of natural transmission routes (wild birds, who doesn't have them around?) + ease of transmission + ease and low expense of vaccination = one more chicken owner that will vaccinate

I've asked locally if Marek's is an issue. Most people have no idea what I'm talking about. But there are three feed stores shipping in hundreds of birds a week to be bought and managed by people that have never given it a second thought. I guess one of these days it will hit.

Canesisters- thanks for posting the helpful links. I was particularly impressed with the story of how Marek's went from being a problem for large operations to now mostly affecting backyard owners because of the husbandry practices. I had also forgotten about the week incubation for vaccinated chicks to develop immunity. Important point.

Keeping the chicks biologically separate (in clean housing, unshared airspace, etc) for three weeks is ideal, from what I understand, but a week is better than nothing!

My vet says that most people are uninformed about it, and wonder why they lose birds form time to time. She told me that while she has only recently started seeing more chickens, most of the 'unknown death' chicken necropsies she does often appear to be Marek's based on tumors and locations of the tumors. I am the first one in years to want actual blood tests run so those past prognoses are based on gross necropsy alone. The general feeling when someone's bird dies for unknown reasons is 'it just happens', which.. of course is true, but it is not the end of the story. Marek's only sometimes presents as obvious signs such as the "splits" paralysis and or/ocular changes in the bird. More commonly a bird simply wastes or even seems to die suddenly and for 'no real reason'. I read the emergencies section of this forum often and I cringe whenever I see someone lose a bird for no obvious reason. Who knows if it's Marek's or not? Unless a necropsy is done at a minimum, you don't. People attribute it to 'just one of those things' and may sell or trade out of their flock without knowing. I know that I am biased now, because I have Marek's in my yard, but I can't help but feel that this could be bigger than we realize in backyard and small farm flocks.

There are arguments against vaccination, too, of course. One of the most important is creating resistant virus strains. This is no small concern, as this does seem to be occurring, and requires a lot of hard thinking. In my small flock, I love my birds as pets, and am unwilling to suffer losses in an attempt to breed immunity (which can be a much longer process than people realize, and seeing a bird go through this.. I'd feel mighty bad doing it on purpose). Even if I did not have pet birds, but livestock only, large losses would be pretty hard to stomach. Marek's is not pretty and the bird seems aware through it's suffering until it dies. I also know that immune birds will still shed, and it would be irresponsible for me to sell them or give away extras. So for me, the choice will always be to vaccinate. However, I do respect people that chose not to, as long as they are educated beforehand and make informed decisions.

 

[seminolewind]

Yes, I read the whole thread! I am very sorry about Trousers. I've been dealing with Marek's for a few years now, and never wish it on anyone. Of course I had a closed flock, only hatched chicks by me. I broke my rule and bought a silkie pullet. Then things started to happen. It was over a year later when I knew for sure they had Marek's.

I am very glad that you posted this thread. I can only imagine how many members have learned from it. As well as the hundreds of lurkers. Aside from dedicated avian vets like yours, we at BYC are all we have for informing fellow members about this virus that really needed to be spoken about.

I have currently gotten brave enough to hatch some of mine and not vaccinate them. I currently have chickens that are either vaccinated or over 4 years old and resistant. But I've had hatches from purchased eggs in the past 4-5 years that were not affected, and I also have a hen that is a 2nd or 3rd generation of resistant non vaccinated. She's almost 3 years old.

You're not alone in this!

 

[Nambroth]

Today in the mail I received the necropsy report and some of the histology. I am sharing them here with you in hopes it helps educate, and maybe in case anyone wants to use it as a resource. The only information I blurred out of these scans is personal information and the personal contact info of some of the doctors, just in case they do not want it to be a matter of public record. I left the different main office contact information intact in case you need to get in touch with any of these folks (My vet, Dr. Wade, said the people in the GA lab were excellent).

Click these images to enlarge (so that you can read them)

First, this is the hemotology report we had done on the last day we took trousers to the vet. While he was resting on oxygen, they took blood and ran some counts. This was just before Dr. Wade was able to contact the laboratory that she had sent the neck mass that she had removed to, so at this point we did not yet know he had lymphoma.


Next, Trousers was unfortunately euthanized after we found out that he had malignant lymphoma, and probably wouldn't even make it a few more days. He was struggling to breathe. It was heart-breaking. I digress. Dr. Wade preformed the necropsy immediately. Ordinarily I would have asked if she minded if I watched so that I could learn, but I was too heartbroken and sleep deprived to even think of asking at that point.
Here is her necropsy report.
I will attempt to transcribe the areas that I can read:

"removed cervical mass 3/11 via surgery - malignant lymphoma. Bird was not Marek's vacc.
Developed sciatic weakness & dyspnea w(ithin) 24 (hours of) surgery. Had severe bradyarrhythmia during anesthesia.
CBS today. leukocytosis with blast lymphs."

Page 2
(Sorry I cut off "body condition, beak and nails, skin, feathers, uropygial, eyes, nares, ears, vent ... all had no comments)


"(Heart) 1cm mass in left ventricle -full (???)
fluid (yellow) in PC sac
(Crop) Surgical site - NSP
(protoventriculus) white nodular irregularities -mucous
(intestine) Small nodules in intestine (???)
(Spleen) Severely enlarged (round) w(ith) multi(??) white masses
(thymus) Present in neck
(gonads) Active testes
(peripheral nerves) Sciatic 5mm wide (wider than femoral artery)
Appear enlarged?
(muscles) some (???) medial thyh


At this point blood samples and organ/nerve tissues were sent to the lab in georgia where additional DNA/molecular testing was done for the presence of any virus.



The initial report from GA:




Histology report on nerve samples. This is significant because some labs, in the past (I don't know if any still do), have visually inspected this nerve via microscope for lesions, thereby indicating Marek's diagnoses. If he had been tested and diagnosed by this sample alone he very easily could have been misdiagnosed. This is important to realize.


The final confirmation of Marek's alone. It was explained to me that ALV (Avian lymphoid leukosis virus), as a retrovirus, works itself into the very DNA chain of the animal. Somewhere, once upon a time, one of Trousers' ancestors had ALV and inserted its "marker" into the DNA of his line. He was not actively carrying/shedding the virus.

 

[artsyrobin]

He was not actively carrying/shedding the virus.

thanks for sharing the details, if he was not carrying and shedding it, does it mean you are safe as far as your flock goes??

 

[Nambroth]

He was not actively carrying/shedding the virus.

thanks for sharing the details, if he was not carrying and shedding it, does it mean you are safe as far as your flock goes??

That was for Avian Lymphoid Leukosis only (which was also suspect but later discovered not to be the case). He still had active Marek's and it goes hand in hand to consider that he actively had and shed Marek's virus.

 

[artsyrobin]

darn, i was hoping that wasn't the case.....