Moving Forward- Breeding for Resistance to Marek's Disease

[sassybirds]

I will try to talk to the senior vet at the lab tomorrow...face to face. Maybe he will be able to shed some light on this disease and how it works in the flock...hopefully he's not "programmed"! I do not understand this 7 year cycle that I have seen referenced to Marek's. I'm even going to carry a list with me! I'll keep y'all updated.

This breeding for resistance is certainly a hard and nasty business. Quite disheartening at times. I just have to keep reminding myself of my end goal...even if it takes longer than I think it should! Resistant birds are attainable!! You guys keep up the hard work!

 

[seminolewind]

Sounds like a nightmare. I'm so sorry. I think the bigger the nightmare the more you know. Sad it has to be that way. Since my nightmaare 3 years ago I have generally lost one here and there, but last year lost two roos and 3 pullets. I have one too who is a survivor and he has good days but then looks bad for a few days then gets himself out of it.

From what I've read an exposed bird is a carrier whether they are resistant or not or vaccinated and exposed will be a carrier too. It's like in two parrts. If any bird is exposed to a MD positive Bird they are exposed and Carry the virus and can infect others. Whether they become symptomatic is something else. The resistance or not seems to be about the symptoms only. Not the virus. In fact the vaccine only protects against the symptoms, not the virus.

 

[seminolewind]

I'm glad you're doing the necropsies. We can all learn a lot from that.

 

[sassybirds]

Sounds like a nightmare.  I'm so sorry.  I think the bigger the nightmare the more you know.  Sad it has to be that way.  Since my nightmaare 3 years ago I have generally lost one here and there, but last year lost two roos and 3 pullets.  I have one too who is a survivor and he has good days but then looks bad for a few days then gets himself out of it.  

From what I've read an exposed bird is a carrier whether they are resistant or not or vaccinated and exposed will be a carrier too.  It's like in two parrts.  If any bird is exposed to a MD positive  Bird they are exposed and Carry the virus and can infect others.  Whether they become symptomatic is something else.  The resistance or not seems to be about the symptoms only.  Not the virus.  In fact the vaccine only protects against the symptoms, not the virus.  

What I don't understand is the amount of misinformation about the disease out there. As one of the most prevalent and deadly poultry disease, one would think there would be more reliable info out there. I have read a lot of muddled, conflicting information. Even the vets seem confused.
I knew there would be mortalities, but not this many so quickly. Wish me luck at the poultry lab!

 

[ChickCrazed]

Question, my necropsy results were inconclusive, but Purdue also didn't actually TEST for Mareks (such a freaking waste of money). So now I am playing the "wait and see" game to see if any other birds get symptomatic to see if I have Mareks in my flock. I have another cockerel that seems to have developed a tumor on his neck. Obviously tumors and Mareks go hand and hand, but I have always heard that Mareks caused tumors on the internal organs, and this seems to be an external tumor. Has anyone seen that before?

I am obviously acting as though I have Mareks in my flock and now have a completely closed flock. For those that have only seen sporadic losses in your flock, how long did you go in between birds becoming symptomatic? With more than 20 birds under 6 months old I would have thought I would have had more showing symptoms at this point. It has been about 8 weeks since the first cockerel had some paralysis.

I think this is a fantastic thread and I agree that for such a prevalent and nasty disease there is not much actual information out there and much of it is conflicting. Culling my flock doesn't seem realistic since the disease could be in the soil now, so I will have to learn to live with it as best as I can and it is great to have this thread to commiserate with.

 

[seminolewind]

Quote:
Since backyard chickens has exploded, while production companies have improved their husbandry and vaccinate, the problem has become prevalent for backyard flocks. Common articles do differ because the article writer lists the "classic" symptoms, not all the other symptoms. It's also their interpretation, and well as chicken owner's interpretation.

Companies have learned that they must vaccinate, practice all in all out, and super disinfecting between all batches, and not mixing ages. Troubles we face is compounded by adopting chickens, getting chickens from swaps and auctions,, adding different ages, not vaccinating, and believing that your flock does not have it because most consider the classic symptoms the only symptoms. There are quite a few on this forum who have been obsessed with finding the true information. Most vets, and hardly any feed store employees do not obsess over it or learn anything at all, and can't give much more information. Even my vet said that my chicken did not have internal tumors so she must have died from EEE. I found it was not true.

The best most concise and correct information I've found is in a book called "Diseases of Poultry" by Chief Editor Y.M. Saik. The chapter was compiled by over 100 scientists/researches.

Nambroth, believe it or not, is the 2nd most precise information posted anywhere in "The Big Marek's FAQ", a link may be found at the bottom of my posts.

Maintaining a closed flock , day old hatchery chicks or your own hatched chicks and no other chickens is probably 99% effective in not getting Marek's. Otherwise, if your flock has Marek's, or you show, or add to your flock , vaccinating and quarantining is the next best thing to save lives. There is nothing more. Breeding for resistance takes time and many deaths to get there. I think some breeds are more resistant to getting the symptoms, but not in being exposed and a carrier.

Keep an open mind about symptoms, there are no rules. The goal right now is to vaccinate all incoming chicks, or day olds. You might as well start by saving lives in your own flock. Be aware that exposure of any chicken lowers their resistance to opportunistic illnesses that a chicken can usually fight off, like coccidiosis, aspergillosis, and common infections.

Send a few for necropsy to confirm. Sassy I will be uber grateful for any info you share about your necropsies. My only necropsy came back negative for Marek's although the bird died from aspergillosis, and had tumors all over internally. I don't believe it. So I will be sending the next few for confirmation.

 

[seminolewind]

Question, my necropsy results were inconclusive, but Purdue also didn't actually TEST for Mareks (such a freaking waste of money). So now I am playing the "wait and see" game to see if any other birds get symptomatic to see if I have Mareks in my flock. I have another cockerel that seems to have developed a tumor on his neck. Obviously tumors and Mareks go hand and hand, but I have always heard that Mareks caused tumors on the internal organs, and this seems to be an external tumor. Has anyone seen that before?

I am obviously acting as though I have Mareks in my flock and now have a completely closed flock. For those that have only seen sporadic losses in your flock, how long did you go in between birds becoming symptomatic? With more than 20 birds under 6 months old I would have thought I would have had more showing symptoms at this point. It has been about 8 weeks since the first cockerel had some paralysis.

I think this is a fantastic thread and I agree that for such a prevalent and nasty disease there is not much actual information out there and much of it is conflicting. Culling my flock doesn't seem realistic since the disease could be in the soil now, so I will have to learn to live with it as best as I can and it is great to have this thread to commiserate with.

I believe Texas A&M has a PCR test (genetic markers?) that needs only blood. You need to send it using the instructions which may mean getting a vet to draw it and put it in the right tube with the right preservative. It may save money, it's $20 for the test and whatever for shipping.

Prior to and following the deaths of all of a hatch, the hatch was 8-6 week olds becoming symptomatic about 5 days apart, some a few weeks apart from paralysis and wasting. My own flock lost a chicken every 3-4 months from wasting mostly they were under 8 months old. This was before and after discovering Marek's.
Last year I lost 2 unvaccinated from resistant parents and another lived. There were 3 others that were vaccinated that I lost at about approx. 8 months old. The spring and fall seem to see more symptomatic birds.

 

[sassybirds]

Okay, so the poultry lab didn't go as planned. The senior vet wasn't there, so I talked to the one that I have already talked to and couldn't only tell me to vaccinate, not any other info. She did seem confused though when I mentioned that I have lost (mostly culled) about 20 birds to this disease in about two months. She seemed to think that it was a little out of the ordinary. It could be something else at work, or just a really virulent strain. As seminolewind said- there is variations in symptoms.

I hope to have necropsy results by the end of the week, or the beginning of next. Will certainly post when I get them.

I thought I'd share the lab report that found Marek's in a 12 week old pullet. This was the first (and so far only) diagnosis. Edited to exclude my personal info

 

[seminolewind]

Sassy, I am so so sorry. They say coccidiosis and Marek's go hand in hand. I think Marek's birds are real susceptible to cocci.

My necropsy looked almost like yours. But my hen tested negative for Marek's PCR (?). I don't see how they could see tumors all over and say she was negative. She did die of Aspergillosis.

I could post my necropsy, but my computer died with all my files and they are stuck in there until I get this thing I can put it's hard drive into and get all my info back.

I can't get over how much it's spread in your hen. But then again, mine did too.

 

[sassybirds]

Sassy, I am so so sorry.  They say coccidiosis and Marek's go hand in hand.  I think Marek's birds are real susceptible to cocci.

My necropsy looked almost like yours.  But my hen tested negative for Marek's PCR (?).  I don't see how they could see tumors all over and say she was negative.  She did die of Aspergillosis.

I could post my necropsy, but my computer died with all my files and they are stuck in there until I get this thing I can put it's hard drive into and get all my info back.

I can't get over how much it's spread in your hen.  But then again, mine did too.

I would have a hard time believing that too...makes you wonder sometimes.

I am starting to wonder if I have a super virulent strain? Would be my luck. Just got the initial report back from the lab (that was really fast!). It seems like there is a lot of info missing....several samples were taken for different things but no results are posted beside them. I don't see any tests for MD?? Ugh. I'll post and see what y'all can make of it.