Avian Leukosis, anybody have experience?

[charlotte-and-the-bees]

I just spoke with my vet and they think we should test for this. Three of my seven girls have had lethargy/unspecified illness resulting in bloodwork and signs of infection. More issues for one of our hens who is on her second course of abx and a heart medication for a murmur. They’re going to draw blood this week to see if we can get a result from that. I’m waiting at the emergency vet right now with another one of our hens who had white liquid diarrhea today and had been extremely lethargic for two days.

I’m honestly just so exhausted and devastated. I practice biosecurity and keep everything very clean, plus check them often and generally just love them. It’s just one thing after another. I know if they are positive for leukosis we will have to keep our flock closed but generally not planning to open it unless we know definitively what’s wrong and it’s treatable. Any encouraging words or experience are appreciated. I’m just not sure what to expect if it is the diagnosis - can they live with it? Will they die almost surely after several weeks?

 

[charlotte-and-the-bees]

@azygous I saw a post that you have it in the flock, what has been your experience with your adult chickens? Mine are all around 1.5 years, not planning for them to hatch chicks.

 

[azygous]

It's not the end of the world as you know it. These avian viruses are not something you want to drop your guard over and permit them getting into your flock, but they can be dealt with.

No, it's not true your chickens are all doomed if you get a leucosis diagnosis. While the virus can produce devastating symptoms, most healthy adult chickens manage admirably to develop resistance to the virus. This means your flock can accept new members, but none can leave to join outside flocks since the most casual exposure means they will carry it for life.

With LL, while there is no vaccine as with Marek's, as long as you take certain precautions with new chicks, they more often than not will develop resistance and won't likely become symptomatic. The only critical period is when chicks are still in the brooding stage and if they consort with an adult carrying the virus and are heavily exposed to viral shed.

I made a thread about what happens when a hen carrying LL covers chicks and they get a heavy exposure to her viral shed while sleeping under her for several weeks. https://www.backyardchickens.com/th...update-now-another-pullet-going-lame.1432738/ Since then, I've added two more groups of new chicks to my flock and all five are so far healthy as I made a point of keeping the chicks from sleeping under a hen. I have two eight-week olds that are being "mentored" by an eight-year old hen who would have brooded them if I had permitted it, but I made sure they were kept separate at night and during the day, made a point to discourage the chicks from getting under her. We shall see if this has been enough.

Over the long term, and I mean years, chickens in my flock have developed leucosis tumors, and these would be much more tragic had they occurred at just a few months or years of age. But these hens, for the most part, led long normal lives and died around eight to eleven years of age. I'd wager their chances wouldn't have been much more optimal in a flock without LL.

 

[azygous]

Just want to clarify something the OP already appears to be aware of, LL is passed vertically from hen to the embryo in the egg. Chicks hatched with LL have a very poor chance of survival. I've tried hatching many eggs in my flock to have most embryos die in the egg, a few that hatched died before age one year. I only have two Legbar/EE mixes survive to a current age of around five years with no health issues apparent. That is not an encouraging track record. I no longer attempt to hatch within the flock. Chicks are imported from hatcheries with a much higher rate of survival.

 

[charlotte-and-the-bees]

Just want to clarify something the OP already appears to be aware of, LL is passed vertically from hen to the embryo in the egg. Chicks hatched with LL have a very poor chance of survival. I've tried hatching many eggs in my flock to have most embryos die in the egg, a few that hatched died before age one year. I only have two Legbar/EE mixes survive to a current age of around five years with no health issues apparent. That is not an encouraging track record. I no longer attempt to hatch within the flock. Chicks are imported from hatcheries with a much higher rate of survival.

Do you have success with certain breeds or hatcheries having good resistance over time? We got the confirmed diagnosis of LL and lost a hen two weeks ago to it. I’m so scared to lose more.

 

[Aunt Angus]

Do you have success with certain breeds or hatcheries having good resistance over time? We got the confirmed diagnosis of LL and lost a hen two weeks ago to it. I’m so scared to lose more.

I don't love your birds' diagnosis, but there's no "empathy" button.

 

[azygous]

The leucosis virus is very very common, so common, many flocks carry it and the keepers never know they have it. The reason for this is because most chickens develop resistance to it and never become symptomatic or live many, many years before they do. A lot of folks who don't know they have LL in their flock think their chicken die of old age.

I am pretty sure it's been in my flock from the time I started my flock fourteen years ago with two adult hens I got from a friend's flock after she died. The hens were around four or five years old. A few months after I adopted them, I had to euthanize one because she became paralyzed. I didn't know it at the time, but she had classic symptoms of LL.

Since then, I've had chickens go lame every so often, but not anywhere near what I would consider frequently. As my chickens age, and most of my chickens live an average of eight years, some develop tumors and need to be euthanized, but it's certainly not a lot of them. They reach ages of eleven and twelve years for the most recent that have died. I still have one of my original baby chicks I got after adopting the first two hens. She's thirteen now and still going strong.

I have the "Whitman's Sampler" flock, all breeds. I use Privett Hatchery. It is true that most popular breeds are now resistant to LL.

 

[charlotte-and-the-bees]

The leucosis virus is very very common, so common, many flocks carry it and the keepers never know they have it. The reason for this is because most chickens develop resistance to it and never become symptomatic or live many, many years before they do. A lot of folks who don't know they have LL in their flock think their chicken die of old age.

I am pretty sure it's been in my flock from the time I started my flock fourteen years ago with two adult hens I got from a friend's flock after she died. The hens were around four or five years old. A few months after I adopted them, I had to euthanize one because she became paralyzed. I didn't know it at the time, but she had classic symptoms of LL.

Since then, I've had chickens go lame every so often, but not anywhere near what I would consider frequently. As my chickens age, and most of my chickens live an average of eight years, some develop tumors and need to be euthanized, but it's certainly not a lot of them. They reach ages of eleven and twelve years for the most recent that have died. I still have one of my original baby chicks I got after adopting the first two hens. She's thirteen now and still going strong.

I have the "Whitman's Sampler" flock, all breeds. I use Privett Hatchery. It is true that most popular breeds are now resistant to LL.

Thank you for this, it makes me feel a lot better for sure. Getting the call today felt like I was getting a death sentence for them despite reading otherwise on here. The vet was a bit more ominous, but it also sounds like she doesn't commonly deal with it (probably because, while she's an avian vet, most people don't take their chickens to the vet period let alone test for LL on living birds...) It's helpful to know about your experience with this. Going to write out my experience so far just for my own sanity of piecing it together.

We got our original 5 from MPC, all different breeds. They were shipped at a day old last spring, all arrived seemingly healthy. We got two more young pullets from a local breeder this spring. All of the originals have been having issues, two new have not yet.

• First hen to have problems was our bantam brahma around the 1 year mark. Started laying soft shell eggs here and there and eventually fully soft shell. She has the suprelorin implant now so fingers crossed that's it, but her bloodwork has shown slightly high lymphocytes
• Second hen to have issues was our bantam cochin, about 2 months ago. Was extremely fatigued and not eating or drinking, brought her to the vet and had toxicity in her blood. Did a course of antibiotics and since has come back relatively normal except for the high lymphocytes. Tested positive for LL
• Third was our ameraucana/faverolles mix, same thing as hen 2, but had fluid build-up in her belly and a heart murmur. Has been on 2 courses of antibiotics and now on heart meds. Tested positive for LL
• Fourth was the mille fleur d'uccle, who was lost two weeks ago. Seemingly normal until she completed her molt, then a quick decline. Still waiting for the histopathology from the state lab but the gross pathology showed liver hemorrhage (with no excess adipose deposits), blood clots adjacent to liver, and pneumonia
• Our 5th hen had a period of fatigue, but a loooong molt. So we never did take her to the vet but has since perked up after molting. She's a silkie. Perhaps some resistance?

I'm extremely meticulous with biosecurity, and the vet's guess is it was transferred vertically to one and horizontally when they were chicks. The newest girls weren't introduced until they were a few weeks old and hopeful the timing helped, though trying to stay cautiously optimistic.

My questions to the vet (they haven't responded), but curious if you have any insight on this given they haven't dealt with it much:

• How does resistance usually look? Are they less likely to contract it period, or early mortality less likely?
• Any reason to test the full flock to see if some are not carriers and separate?
• Vet mentioned any stressful event can cause it to worsen quickly. We're moving in February and I'm really nervous for this. Any tips to ease this stress?
• We just started doing deep litter, would it be advisable not to do this?

Sorry this is a wall of text, I appreciate you and this community so much!

 

[charlotte-and-the-bees]

Now I’m reading more about it and really worried the new hens brought it in. The farm is reputable and NPIP certified but the timeline matches. I feel awful.

 

[TheOddOneOut]

Now I’m reading more about it and really worried the new hens brought it in. The farm is reputable and NPIP certified but the timeline matches. I feel awful.

NPIP does not mean disease-free. There can never be a 100% guarantee. Unfortunately, this is probably what happened.