ALV (Avian Leukosis Virus) help!

[Shellebelle920]

Can anyone point me in the direction of some good articles about ALV. I am aware that this virus mimics Marek’s but can be transmitted through the egg. I hatched a bunch of chicks from 4 well known breeders in the Spring of 2021. After some mysterious deaths last summer, I sent a hen off to get necropsied. The vet said there were lesions consistent with Mareks. I lost another 22/35 chickens over the winter. However my older girls who are housed separately all stayed perfectly healthy. I came to terms with the fact that my flock has Mareks and was planning on hatching, vaccinating and starting to build some resistance this Spring. But before I hatched, I wanted to be sure that I was 100% dealing with Mareks. So I sent off blood and cloacal samples to RAL laboratories to be tested for Mareks and ALV. And quite surprisingly, both of the samples (one from my only remaining Faverolles and only remaining buff Silkie hen) came back NEGATIVE for Mareks, but the Buff silkie’s sample came back positive for ALV. The Faverolles was negative. So I’m lost as to where to go from here. Is best practice to cull this entire Spring 2021 hatch (13 birds left)? I definitely won’t be hatching from the buff Silkie, but is the Faverolles safe to hatch from? The Faverolles and Silkies are cooped together but currently separated for breeding. Thank you for any help!

 

[Stipenvlerk]

What a decision to make. pfff I don't envy you..

I found an article about eggsize and AVL. Not completely related but a nice read
https://pubmed.ncbi.nlm.nih.gov/19184859/

 

[Perris]

@azygous has dealt with this for years and has written articles and threads about it. Search for things by her on this site.

 

[Shellebelle920]

What a decision to make. pfff I don't envy you..

I found an article about eggsize and AVL. Not completely related but a nice read
https://pubmed.ncbi.nlm.nih.gov/19184859/

Thank you. I will take a look at it.

 

[Shellebelle920]

@azygous has dealt with this for years and has written articles and threads about it. Search for things by her on this site.

I will do that. Thanks for the help!

 

[azygous]

Your question whether it's safe to hatch from the SFs, I'd say no. Avian leucosis is as contagious as Marek's, and is passed from hens to embryos in the eggs. In my flock, past experience says hatching from the flock is the most lethal way the virus is passed. My mortality rate is over 90% for chickens hatched within my flock. In fact, only two chickens ever survived into advanced adulthood.

Culling the remainder of your flock, since you're a breeder, would be the most practical, though it's not what I've done. Most chickens develop resistance to avian leucosis, so my flock is closed and getting by just fine. But my management of leucosis in my flock wouldn't be practical if I were keeping chickens to breed.

 

[Shellebelle920]

Your question whether it's safe to hatch from the SFs, I'd say no. Avian leucosis is as contagious as Marek's, and is passed from hens to embryos in the eggs. In my flock, past experience says hatching from the flock is the most lethal way the virus is passed. My mortality rate is over 90% for chickens hatched within my flock. In fact, only two chickens ever survived into advanced adulthood.

Culling the remainder of your flock, since you're a breeder, would be the most practical, though it's not what I've done. Most chickens develop resistance to avian leucosis, so my flock is closed and getting by just fine. But my management of leucosis in my flock wouldn't be practical if I were keeping chickens to breed.

Thank you for the response and sharing your experience. I can’t say I’m a breeder, because these chickens got sick before I ever really had a chance. This batch from Spring 2021 would have been my first generation to breed although I have older chickens as layers. However, I really like the buff color of Silkies and the Faverolles, so before I realized it was ALV, I thought I could start building some resistance and working with these two breeds. I’m not going to hatch and, I’ll give it some time to decide whether to let them live out their lives or cull. Such a bummer!

 

[azygous]

Yes. it is a bummer. Believe me, I know the dilemma. Working around an avian virus is not what I would wish on any flock keeper, but it can be done if you don't want to cull. LL is an avian virus that is so common, it's in flocks every where and the flock owners aren't even aware it's in their flocks.

Most LL flocks are normal, chickens are usually quite healthy, but hatching from within the flock is where the real heartache occurs. At some point, the decision is made not to try to hatch. Then things proceed as if the flock were normal.

 

[lisa69]

Your question whether it's safe to hatch from the SFs, I'd say no. Avian leucosis is as contagious as Marek's, and is passed from hens to embryos in the eggs. In my flock, past experience says hatching from the flock is the most lethal way the virus is passed. My mortality rate is over 90% for chickens hatched within my flock. In fact, only two chickens ever survived into advanced adulthood.

Culling the remainder of your flock, since you're a breeder, would be the most practical, though it's not what I've done. Most chickens develop resistance to avian leucosis, so my flock is closed and getting by just fine. But my management of leucosis in my flock wouldn't be practical if I were keeping chickens to breed.

I hatched eggs accidently thinking I had Mareks. It turned out to be AVL. I have first generation hens, positive, 2nd generation hens ALV positive( i hatched them by incubator) and now 10 month olds in a clean room that are perfectly healthy. So I am confused. parent birds were PCR tested at RAL labs. I'm going to test generation, after the holidays.

 

[lisa69]

update. I have had no new losses in the last 2 hatches, of 1st generation and second generation, from my positive hens. they are 8-10 months old. The Cream leg bars and all laying eggs, but my deathlayer pullets are not yet. Not sure why these new sets of chickens are doing well. The first hatch I set loose with my flock, last summer suffered 50% losses. But the survivor's progeny are doing well.