Lost 2 chickens in past 2 weeks -- now have hen paralyzed w/ different symptoms from other birds


Aug 28, 2021
Hi All!

My chickens are a part of my family. I feed them organic food, organic scratch and they get healthy/chicken-safe scraps and dried meal worms. They do not have any access to toxic plants. Regularly have access to ACV water and also plain water (from well, no hard minerals, great water -- did water test for our goats and came back great.)

Up until this point, all of my chickens have been healthy and strong. Located in Western Washington.

All of our birds were vaccinated against Mareks (although from reading, I know the vaccine is not a guarantee a bird will not get the disease/exhibit symptoms, as it's a leaky vaccine.)

1) What type of bird , age and weight (does the chicken seem or feel lighter or thinner than the others.).
RIR, 3.5 years old, ~6 pounds, normal weight compared to other birds, vaccinated against all 6 subtypes of Mareks.

2) What is the behavior, exactly. RIR's legs are weak/she appears to be partially paralyzed. Leans slightly to one side but her legs are not split in classic Mareks. Has trouble moving around, using wings for balance. Does not have bumblefoot. Eating and drinking normally. Comb is red and she is bright, alert and reactive. Laid 2 eggs the past 2 days. Not in any signs of discomfort other than struggling to get around. Chattering and talkative. Currently have her isolated away from the rest of the flock.

3) How long has the bird been exhibiting symptoms? 3 days. The first day she was able to walk but stumbling a bit like she was drunk. 2nd day, completely lost feeling/ability to move legs. Partner is former animal wildlife rescue trained/worked at a zoo and has been moving her legs 2x per day to promote bloodflow/prevent clots. Partner noted no resistance/push back from hen on day 2 when moving her legs. This morning, partner moved hen's legs and noted improvement and stated legs were stronger/got resistance/push back. Hen also perked up and flapped her wings this morning.

4) Are other birds exhibiting the same symptoms? No. That said, 2 weeks ago, our 3.5 year old rooster (EE) passed away very suddenly. No, although have lost 2 birds in the past 14 days. 4 days before he passed, his crow changed (became hoarse), was listless, tailfeathers quivered and was lethargic. No sign of gurgly breathing/respiratory infection. Able to stand/walk until he died. Died of a seizure. Did not take his body to get necropsied.

A different RIR (also 3.5 years old) became ill shortly after rooster died (~2 days later.). Pale comb, unresponsive, sour crop. Took the RIR to be put down and have her body necropsied. Still waiting on results, although initial results showed massive infection throughout entire body and a backup of eggs.

5) Is there any bleeding, injury, broken bones or other sign of trauma. No.

6) What happened, if anything that you know of, that may have caused the situation.
Rooster used to kill birds/mice/rats. Possible botulism toxicity?
Galvanized water container slightly rusted -- possible zinc toxicity?
Possible Marek's? Or other type of infection? Hens are able to interact with wild birds.
Possible heavy worm infection? (Prior to current deworming, last time dewormed was ~ a year ago w/ copper sulfate.) -- possible rouge worm on spine?

7) What has the bird been eating and drinking, if at all. Yes. Eating and drinking normally. Very. hungry. Crop emptying normally.

8) How does the poop look? Normal? Bloody? Runny? etc. Normal.

9) What has been the treatment you have administered so far? Isolation, dewormer, ACV water,

10 ) What is your intent as far as treatment? For example, do you want to treat completely yourself, or do you need help in stabilizing the bird til you can get to a vet? Would like to treat completely by myself unless the bird goes downhill and needs to be put down.

11) If you have a picture of the wound or condition, please post it. It may help. N/A

12) Describe the housing/bedding in use. Currently confined in a dog crate. Local grass used as bedding. In coop, there is a wire/mesh bottom

Thank you so much in advance for your thoughts!

Please let me know if there's anything I might have missed.
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A lot will hinge on the results of your necropsy. There are common markers in a dead chicken's organs and nerves that will point to either Marek's or lymphoid leucosis. While each of these avian viruses are very similar, the absence of one common marker, for example an absence of an enlarged sciatic nerve may point to lymphoid leucosis, while the absence of an enlarged liver may point to Marek's. And it does sound like you may have one of these viruses in your flock.

I hope the necropsy also includes a pathology panel. That can tell you if your suspicions of botulism toxin or a related pathogen may be warranted.

On the "leaky" Marek's vaccine, this is poorly understood by many. I think you may be among the few that is very close to getting it. The Marek's vaccine is not perfect. It only provides a boost to a chicken that has received the vaccine so they can develop resistance to the virus and whichever strains were included. A vaccinated bird can still get the virus if they are directly exposed to it. That bird can then infect an unvaccinated bird with the virus. Attaching the word "leaky" to Marek's vaccine is really a misnomer.

I have lymphoid leucosis in my flock. The past year, I battled three symptomatic cases in my flock involving young pullets. Normally in the past, the young birds that were overcome by the disease had been exposed to it in their egg during gestation or were older birds whose resistance to the virus had run down. These pullets were infected directly by a broody hen after she adopted them at around four weeks of age and they were heavily exposed to her viral shed as they were covered by her at night. Only one pullet survived, probably because she was the only one who chose to sleep beside her, not under her. My thread on this is an interesting journey of trying to figure out the "mystery illness" and ways I tried to treat it, and it includes the necropsy findings that finally pointed directly at the virus that was in my flock all along. You might find it interesting to compare to yours. https://www.backyardchickens.com/th...update-now-another-pullet-going-lame.1432738/

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