lymphoid leukosis - what next?

[Kkrejci]

Hello all, I have a flock of 45 chickens and about half of the chickens that I hatched last spring have randomly plopped over dead as they neared egg-laying age. All of my adults remain healthy with no issues. I finally did a necropsy and revealed a massive liver with white tumors in it (see photo). Everything else looked fine except for fairly atrophied intestines. No evidence of any egg production. I highly suspect lymphoid leukosis.

I have a few roosters, so I like to incubate my eggs each spring... but, now I'm not sure what to do since it looks like the virus can spread down from the flock to the eggs from the reading I've done. I saw a few people mention that it's safe if you only use the eggs from hens that have gone through 2 molts? Is that true?

I also have a few orders in for chicks from a hatchery... will they be safe bringing them in? I'm at a loss as to what to do. I really don't want to have to cull my flock especially with so many adult birds that seem quite healthy.

Any help would be greatly appreciated! Thank you!

 

[Sally PB]

@azygous has first hand knowledge about LL.

 

[Kkrejci]

@azygous has first hand knowledge about LL.

Thank you so much! Hoping to hear a reply from them

 

[azygous]

This demystifies the leucosis virus. https://www.poultryhub.org/all-about-poultry/health-management/disease/lymphoid-leukosis

Hatching from within a leucosis flock is one of the main means the virus spreads (and kills). So I don't do that anymore. I buy hatchery chicks from my local feed store and brood them in proximity to the flock. They are exposed to the virus but not in such huge amounts that it causes them to become symptomatic. All my new hatchery chicks have gone on to develop resistance and lead normal lives and life spans.

I did allow a broody hen a couple years ago to adopt four hatchery chicks. I lost three of them at around five to seven months of age because the hen had become symptomatic but I hadn't noticed. The chicks received a massive viral shed from the hen as she covered them. The survivor chose to sleep beside the hen and not under her, and I figure it's how she escaped getting a lethal exposure. She's alive and well nearly three years later.

So, go ahead and get chicks. They should develop resistance and be just fine.

The liver shown above does appear to be the classic presentation of leucosis. And I think the advice about it being safe to use eggs from a hen carrying ALV after the second molt is what I like to frame as something someone has mined from the vestigial brain in their posterior region.

 

[Kkrejci]

This demystifies the leucosis virus. https://www.poultryhub.org/all-about-poultry/health-management/disease/lymphoid-leukosis

Hatching from within a leucosis flock is one of the main means the virus spreads (and kills). So I don't do that anymore. I buy hatchery chicks from my local feed store and brood them in proximity to the flock. They are exposed to the virus but not in such huge amounts that it causes them to become symptomatic. All my new hatchery chicks have gone on to develop resistance and lead normal lives and life spans.

I did allow a broody hen a couple years ago to adopt four hatchery chicks. I lost three of them at around five to seven months of age because the hen had become symptomatic but I hadn't noticed. The chicks received a massive viral shed from the hen as she covered them. The survivor chose to sleep beside the hen and not under her, and I figure it's how she escaped getting a lethal exposure. She's alive and well nearly three years later.

So, go ahead and get chicks. They should develop resistance and be just fine.

The liver shown above does appear to be the classic presentation of leucosis. And I think the advice about it being safe to use eggs from a hen carrying ALV after the second molt is what I like to frame as something someone has mined from the vestigial brain in their posterior region.

Thank you so very much for your thoughtful and helpful reply! I am encouraged that my hatchery chicks should do well.

However, being able to breed my own birds and use broody hens to hatch/raise the chicks is something that brings me a lot of joy and is a big part of what I do with my chickens. Is culling my flock, sanitizing, and then starting fresh with a new flock the only way to get back to that? Or, will it be possible again after a few years as long as I only bring in hatchery chicks in the meantime?

I so appreciate all of your help as I can't seem to find the answers to these questions anywhere!

 

[azygous]

No, ALV will always lurk in the cells of your flock. It won't magically disappear, although many years of resistance in your flock may give that illusion.

I harbor a sadness that I won't be able to have the joy of watching a broody hen with the babies she hatched and raised. But then I fondly gaze upon my flock of irrepressible individuals and rejoice in their health in spite of the deadly virus they carry in their cells. It more than compensates for not hatching chicks from my flock.

You certainly may choose to cull your entire flock and begin anew. The relatively short lived nature of the leucosis virus makes this very practical. Whereas Marek's can survive as viable in the soil for a year or even two years, ALV will become neutralized in just a few weeks. Cull the flock, scrub down the coop, wait a month, and start a new flock.

 

[Kiki]

Hello all, I have a flock of 45 chickens and about half of the chickens that I hatched last spring have randomly plopped over dead as they neared egg-laying age. All of my adults remain healthy with no issues. I finally did a necropsy and revealed a massive liver with white tumors in it (see photo). Everything else looked fine except for fairly atrophied intestines. No evidence of any egg production. I highly suspect lymphoid leukosis.

I have a few roosters, so I like to incubate my eggs each spring... but, now I'm not sure what to do since it looks like the virus can spread down from the flock to the eggs from the reading I've done. I saw a few people mention that it's safe if you only use the eggs from hens that have gone through 2 molts? Is that true?

I also have a few orders in for chicks from a hatchery... will they be safe bringing them in? I'm at a loss as to what to do. I really don't want to have to cull my flock especially with so many adult birds that seem quite healthy.

Any help would be greatly appreciated! Thank you!

Just wondering/curious...
You did the necropsy yourself of you have a state lab tell you that you are indeed dealing with this one disease?

 

[Kkrejci]

No, ALV will always lurk in the cells of your flock. It won't magically disappear, although many years of resistance in your flock may give that illusion.

I harbor a sadness that I won't be able to have the joy of watching a broody hen with the babies she hatched and raised. But then I fondly gaze upon my flock of irrepressible individuals and rejoice in their health in spite of the deadly virus they carry in their cells. It more than compensates for not hatching chicks from my flock.

You certainly may choose to cull your entire flock and begin anew. The relatively short lived nature of the leucosis virus makes this very practical. Whereas Marek's can survive as viable in the soil for a year or even two years, ALV will become neutralized in just a few weeks. Cull the flock, scrub down the coop, wait a month, and start a new flock.

My heart is heavy with the decisions in front of me - I will need some time to think carefully through all of the options. I wholeheartedly thank you for taking the time to talk through this with me - I have been unsuccessful in finding anyone with experience or knowledge about lymphoid leukosis.

I'm lucky in that I have a large coop and run that is separated in half so I can separate my flock as needed for breeding, raising chicks, etc. I'm wondering... if I kept my existing flock on one side to let them live out their days, then purchase hatchery chicks and raise them on the opposing side... Could I then use those hatchery chicks for future breeding/brooding assuming that they'll develop natural resistance through mild exposure and be healthy? Or would that method only provide an option for "healthy" birds, but still eliminate any possibility of breeding/brooding so long as the affected flock is next door?

Thank you again for your help.

 

[Kkrejci]

Just wondering/curious...
You did the necropsy yourself of you have a state lab tell you that you are indeed dealing with this one disease?

I did the necropsy myself. We've raised hundreds of pastured meat chickens throughout the years, so I'm pretty comfortable with chicken anatomy. I saved the liver in our freezer in case I need to send it in to confirm, but I'm 99% confident that it's lymphoid leukosis.

 

[azygous]

You need to rethink your logic. The line of thinking you are pursuing would still leave you with a flock carrying the virus. It cannot be controlled and contained within the same premises. It spreads by dander and dust on the air currents, on your shoes and clothes and even hands. The new chicks will pick up the virus in this manner.

These new pullets will then carry the virus. You still have infected hens passing the virus to the embryo in the eggs. All hens carrying the virus will pass it to the embryos. You would not be able to sell any of these eggs for hatching purposes or hatched chicks.

It's like trying to have it both ways and the virus has its own rules. It won't work.