Mareks: Long-term prognosis

[seminolewind]

Some "experts" have not kept up with where the problems are. Over the years , commercial producers have been using practice measures to control Marek's, like all-in-all-out, vaccination, disinfecting the premises between hatches. Backyarders have not. Now our problem is growing mainly because we have not been practicing those measures, and most chicken peole not knowing that there's a massive problem, not knowing that there a alot of symptoms other than one-foot-forward-one-back, thinking that this is the only symptom. Also , adding vaccinated birds that have no symptoms but are carriers.

From what I've read, most chickens contract Marek's from other chickens.; Large amounts of chickens not even a mile away , it would be less likely, as well as wild birds carrying it in. But not impossible.

Since all my chickens were hatched here or from a nursery EXCEPT FOR ONE, I have traced it back to that one. The closest chicken to her died with paralysis , grey eye, wasting, and lost control of neck. On the end he had the forward back legs. From then on I lost a chicken from wasting away every 3-4 months (while eating and acting normal).

Don't discount your flock history.

 

[centrarchid]

Some "experts" have not kept up with where the problems are. Over the years , commercial producers have been using practice measures to control Marek's, like all-in-all-out, vaccination, disinfecting the premises between hatches. Backyarders have not. Now our problem is growing mainly because we have not been practicing those measures, and most chicken peole not knowing that there's a massive problem, not knowing that there a alot of symptoms other than one-foot-forward-one-back, thinking that this is the only symptom. Also , adding vaccinated birds that have no symptoms but are carriers.

From what I've read, most chickens contract Marek's from other chickens.; Large amounts of chickens not even a mile away , it would be less likely, as well as wild birds carrying it in. But not impossible.

Since all my chickens were hatched here or from a nursery EXCEPT FOR ONE, I have traced it back to that one. The closest chicken to her died with paralysis , grey eye, wasting, and lost control of neck. On the end he had the forward back legs. From then on I lost a chicken from wasting away every 3-4 months (while eating and acting normal).

Don't discount your flock history.

It the business of what is written above that I consider to be suspect. Wild birds to my knowledge have not been assesed. This needs to be done. The wild birds are made up of many species that are not as closely related to each other as susceptable chickens are to resistant turkeys. Therefore multiple song bird species need to be assesed. I suggest the list include but not be limited to warbler spp., sparrow spp., English house sparrows, European starlings, timberdoodle, American robin, bobwhite quail, red-winged black bird, common and great-tailed grackles, cardinal, mocking bird, towhee, grey junco, mourning dove, blue jay, American crow, red-tailed and Coopers hawks, and greathorned and barred owls. All of the above plus other less frequently seen species interact with or occupy the same ground with my flocks.

 

[seminolewind]

I have jays and crows. I have no doubt at all that wild birds can carry Marek's. I would think that if wild birds came across Marek's in chicken dander and dust, and carried that with them physically, they would infect the ground at the next flock.

But , is a wild bird or birds capable of carrying enough virus to wipe out a flock? The amount carried by a little bird may or may not be enough virus to infect a flock vs. a chicken in the flock actively spewing dander and dust.

I guess that would have to be worked on as well.

 

[centrarchid]

Small bird need not infect entire flock directly, rather just one chicken and then disease spreads from there.

 

[seminolewind]

You think? Another member last year was talking about the amount of available virus. Talking about cleaning to lessen available virus. The other thing is that my carrier silkies hatched 10 Polish eggs I bought and they all died starting at 8 weeks. But I've hatched other chicks and they were in a coop further away and were not affected.

When will they ever get around to that research???

 

[snowflake]

I do not know if the exposed but otherwise assymptomatic birds will be long-term carriers although literature I have suggest they will be. I am also not confident that true resistance will be case in all assymptomatic birds since environmental stress can cause birds to come down with condition. My outbreaks have been very consistently occuring during fall so weather changes may be important. Another possibility is another reservoir for disease operates in my situation, not just my flock. Outbreaks also coincide with fall migration of songbirds that by free-ranging flocks do come into contact with. Some of those birds are dying on my property each year and the chickens will at least play with bodies if not consume them. When I discussed this possibility with one of our state poultry health experts he discounted that possibility out of hand but his thought processes seemed restricted to commericial producers operating intensive indoor systems. The contact between migrant songbirds and chickens did not seem to register. When outbreak is repeated next season I will take dead / sick songbird and symptomatic chicken samples for analysis. According to how they charge, the number of birds does not matter and rules say nothing about species either so should all be done for same price. I may need to get permit for songbirds so they can be legally handled.

very interesting study, I hope I catch the results. Maybe you could get it published in backyard poultry mag. or something. You sound like you have studied this a lot. My hats off to you.

 

[blackthistle]

Peter Brown, DVM, suggests vaccinating birds immediately upon showing clinical signs. It may help and I would definitely do that as soon as possible.

My other vet from Tufts University insisted the birds get revaccinated yearly. I have been doing this, and it is worth it. There really are no side effects of the Marek's vaccine. I vaccinate every one of my birds for Mareks every year. The vaccine does wear off. Vaccinating chicks only is not enough.

 

[babsbag]

Don't be so sure there is no side affect from vaccinating. I vaccinated a perfectly helathly 1 year old barred rock and that was the last day she laid an egg. She is still with me, sitll healthy, but up until the vaccine she had been laying an egg every day all winter long. Coincidence? who knows.

I have hatched out birds with broodies and have had them remain healthy, I have had hatchery vaccinated chicks die as they get older. I don't know that it is all Marek's without some extensive tests. The hatcheries are still telling us that it is rare in backyards flocks and yet I see posts on BYC almost daily where someone is suspecting Marek's. I know that lympohid leukosis has the same symptoms and usually affects older birds. I think it is possible that there is more than one insidious disease at work here.

 

[leadwolf1]

I disagree with the hatcheries....they are not looking at new data. I know for a fact, through necropsy, that my birds have Marek's. I have no idea where it came from. No chickens have ever been in this yard....

The state lab didn't even flinch when they gave me the diagnosis...not, wow, this is rare! On the contrary, she seemed as if it were just another in a long line....

It's out there and it's real.

 

[seminolewind]

Peter Brown, DVM, suggests vaccinating birds immediately upon showing clinical signs. It may help and I would definitely do that as soon as possible.

My other vet from Tufts University insisted the birds get revaccinated yearly. I have been doing this, and it is worth it. There really are no side effects of the Marek's vaccine. I vaccinate every one of my birds for Mareks every year. The vaccine does wear off. Vaccinating chicks only is not enough.

I thought Mr. Brown was not a Doctor, it was just a nickname as "The chicken doc".

Once exposed, either by vaccine or disease, the blood starts building an "army" to fight Marek's deadly side effects. It's a matter of which exposure is first-the benign exposure vaccine, or the disease. With the vaccine, it's also important to protect the chicks from Marek's exposure for a few weeks. The vaccine only protects against the deadly side effects, not the disease. So it can still be spread from vaccinated chicks.

Mr. Brown has speculated about using the vaccine on adults or adults showing signs, but makes no recommendation. I also have a University reference book that also speculates about vaccinating adults, but it, too, has never seen proof that it works. The Germans vaccinate again several weeks after the first vaccine, if there has been no exposure.