Why Old Hens Die

I have several hens that will be seven years old this spring. That’s old, very old, for chickens. Although you might hear of a hen that lived to be thirteen, that’s the exception to the norm. I routinely read “chickens live to be eight to twelve years of age.” It’s like saying, “My grandmother lived to be 102, so all grandmothers live that long.”  The real truth is that hens usually die much younger than that. As a chicken keeper, you can expect to lose birds to predators. Some chickens die in accidents;  I had a chicken fall off a roost and break her neck. Chickens die from respiratory ailments. They mysteriously die around the age of three. They die from egg-laying screw-ups, like internal laying and prolapse. But, sometime, they skirt the dangers and make it into old age.

I currently have chickens that are elderly. Edwina, a Barred Rock, is a little stiff and slow, but she’s still scratching the ground, actively feeding, and maintaining her status in the flock. She hasn’t laid an egg for two years (since she was five) but she’s earned her retirement. Her sister, Eleanor, has not aged as gracefully, and has appeared to be at death’s door for over a year. I have to trim her nails because she doesn’t wear them down in the dirt – she spends most of her time lying in the sun. She walks like a person achy from arthritis.

This year I’ve had two older hens die. I’ve done necropsies. Inside, the birds were filled with tumors and enlarged and damaged ovaries. There are two common viruses that attack chickens that are known to cause tumors – Marek’s and lymphoid leukosis. To determine if either of these diseases were responsible, I recently had three birds blood tested. The results were inconclusive, but interesting. Blackie, a 7-year old Australorp who I’m sure is going to die any day now (but she keeps proving me wrong), was vaccinated as a chick for Marek’s. The Marek’s vaccine wears off after a few years, so that old hens who missed Marek’s as pullets can die of it when they are older. However, the blood test showed that Blackie remains free of that virus. The other two tested hens, who are younger and were purchased from breeders who don’t vaccinate, do have traces of Marek’s in their blood, but do not exhibit symptoms. Blackie does test positive for leukosis – as does one young hen, but not the other.  These viruses are shed in fecal matter and feather dust. They’ll always be on my property. They’re ubiquitous and are probably on yours. What the blood tests show is that some birds will get the viruses and others won’t. It’s a matter of genetics, constitution and vaccination.

I’m not convinced that it was Marek’s or leukosis that did in my birds. There’s another possible culprit – adenocarcinoma. Adenocarcinomas are malignant tumors, also caused by viruses that chickens are prone to. In fact, one research paper stated “laying hens are subject to the spontaneous development of ovarian and oviductal adenocarcinomas.” A vet that looked at photos that I took of Petunia’s necropsy though that she had a diseased and ruptured ovary. It sounds like adenocarcinoma to me. These tumors are so prevalent that scientists studying human ovarian cancer use chickens in their research. A study in 2005 of 676 four-year old laying hens determined that 45% had tumors! 18% of those were adenocarcinomas.

In the end, I don’t know what specific virus is causing the tumors in my old hens. For my purposes, it doesn’t matter which one it is. Care and outcome is the same. However, I do want to do everything I can to keep the viruses at bay. Keeping the barn clean and swept of dust reduces the viral load in the environment. Caring for my chickens so that they are in optimal health helps them resist disease. Also, I’ll buy vaccinated chicks (which reduces incidence of Marek’s in young birds by 90%.)

Knowing how prevalent tumors are in older hens confirms how sensible the farming model is of keeping laying hens until the second molt, and then harvesting them for meat. After that, egg production isn’t high enough to be economically viable, and too many chickens wouldn’t be edible, even for the stew pot. If I was a real farmer, that’s what I’d do. But, I’m not “sensible” here at Little Pond Farm. Blackie and Eleanor look uncomfortable, but not in pain. They eat, they roost, they cluck their approval of special treats. These old hens will live out their days. And, maybe Edwina will make it to the chicken equivalent of 102.


  1. I have a hen I watch daily and just don’t know how to help her. She went through her molt in the Fall and has not been able to grow feathers back. She keeps losing more and more and her skin is very red. I read your blog daily and learn so much, but it really does take a while to learn how to care for chickens. We only have one vet in our area, that I’m aware of, who will take care of chickens. Because mine free range daily, I worry mostly about predators. But it seems the other health issues can be the more difficult to figure out and treat. I didn’t know about Marek’s but I will ask our farm store during March Chick Days…..coming soon!! Thanks for posting information that can be so helpful to chicken gals like me:-)

  2. Terry, thanks once again for posting all the very helpful information/research data you have unearthed. My experience with my hens that have died on their own is that they were around three– two of them died from internal laying and the third I think from exhaustion. She was my best layer– once she started laying, she never took a day off and laid enormous eggs for her size. Currently I have four hens: one who is 5, two who are 4, and one who is 3. I am curious to see how my 5 year old Rhode Island Red ages… she is my nine-lives chicken and is STILL laying eggs fairly regularly! In the winter mornings, she can be a little stiff, but I think that could be more from an injury she sustained in a fox attack three years ago than old age.

    Anyway, thanks for all you do in keeping us informed, entertained, educated and let’s not forget amused!

  3. I think the normal life time age for most chickens is between three to six years. The oldest chicken ever Matilda died at age 16, according to Guinness World Records. And she lived inside all her life as well. I think genetics if a big factor as well, I think bantams or decorative type chickens live longer than egg or meat chickens, simply for the fact their body isn’t as much from egg laying. It will be intresting to see how long your Polish live.
    Hopefully one day their will be a vaccine for every virus a chicken can get against having tumors, espically if the trend of keeping chickens as pets continues.

  4. I have two Americauna bantams, at five years old they both lay an egg every other day only pausing for molt and broodiness. The rest are heavy breeds, 14 hens, 1 roo. They are all going to be 3 years old in June. They are laying very well, getting about 7 eggs a day, and are healthy. I would love to set one of the bantams on a few eggs this spring, and will see to getting some “replacement” chicks to grow on this summer. I have visions of them all dropping off the roost on their third birthday! I love every chick I see, so it will be difficult to pass any up at the chicken swap in March!

  5. I especially enjoyed this post, very informative. Thank you.

    I remember a vet telling me when one of my older hens was ailing…that once they decide (for whatever the reason) to shutdown they will, so as long as they are eating and still acting as a hen then let nature takes it’s course.

    I have brought more than a few to be euthanized…couldn’t do it myself, but most of the others have died peacefully on their own.

  6. Thanks for sharing more information with us- it really is helpful! For an update on Maizy, she is still with us, but yesterday her feathers began falling out by the handful- beginning with that bloated belly. Her pecking is becoming erratic, and she put herself to bed long before the other hens came in from their outing in the yard. I fear the end is near.
    A friend wondered if this could be coccydosis(sp?), and maybe I should treat the others?

  7. I’m glad everyone has found this useful.
    Maryanne- I don’t think that chickens experience illness and pain the way we do. It’s like there’s a disconnect so that they can continue to function (and not make themselves more obvious as a weak preyed-on animal.) With chickens, if they continue to be able to roost, they’re still okay. It’s not until the very end of their lives that you see that panicked or defeated look in their eyes.
    Tracy, I doubt that it’s coccidiosis. I’m sure your hen has an internal problem, maybe ascites, maybe tumors due to one of these viruses. You’ve done what you can.

  8. Kit, I couldn’t agree more with your reasoning on bantams and ornamental type chickens. I’m 48 and have been around or raised chickens all my life except the 5 years in college,yes I was on the five year plan, I had too much fun the first year or two ;-)
    I have always had two flocks, a fun flock that contains all types of birds and a production flock that I have for egg production and then cull at approx. 30 months.
    The dual purpose and/or egg production birds in my “fun” flock never seem to make it past four, sure I have exceptions but not many. I just lost a Polish that was 8 and have one that is currently 5. I have several black jap bantams that are 8 and several old english game bantams that range from 6 to 9 years of age.
    This year, however, it’s been predators that have hit me the hardest. I had to cull a speckled sussex last night due to a coon attack the other day in broad daylight. Now that the temps are in the high 60’s and low 70’s and the snow pack is gone I’m hoping these varmits can return to a normal prey menu and normal routine.

    Once again Terry excellent information.

  9. Terry, I am so thankful that you’re looking for answers in such scientific ways…. We all want to know the answers, but I for sure would have a tough time looking for them the way you do!

  10. I lost a bantam flock to lymphoid leukosis. Purdue University did the confirming necropsy. So sad. I have never had a chicken live past 3 years either. My Orpington girls are almost 3, and I suspect I may lose one to egg laying problems. For now, they are living a contented life as pet chickens in my backyard!

    • Bonnie Jo- what symptoms did you see? And how old were they? Marek’s and leukosis tend to take out entire flocks when the birds are young. It happens quickly. For the older hens, the course appears to be slower, with many tumors forming.

  11. My chickens are only 2 years old, so no losses yet. I am paranoid about night time predators so their coop is like Fort Knox. And on a happier note, i got 5 new baby black copper marans that are now 3 weeks oid. They are living in a big box in the greenhouse with their infrared heat lamp. I’ve told the big girls that they have competition, but they don’t get it yet.

  12. Terry, I know you are very knowledgable about birds. I wanted to know if it was true that ducks were naturally immune to disease like those.

    • Jam- I don’t know much about ducks. Only a few of the chicken diseases apply to all birds. Many are species specific. I’m sure ducks have their own issues!