Skipped molts - trying to figure out why

[DonyaQuick]

Another update on these two birds: both are finally nearing completion of their molts (I hope anyway). Both became very start-stop-start about it again for unknown reasons since my last post. No signs of worms this time. Then, offset by about 2 weeks, they each had some kind of catastrophic metobolic shutdown that required special care: inability to maintain body temperature (shivering and hypotheria symptoms at 50F ambient temp), inability to digest food properly, and eventually refusal to eat/drink resulting in dehydration. They both had extreme and rapid weight loss that, this time, seemed to have nothing to do with worms based on DIY fecal float and zero evidence of proglottids. I worry whenever a hen drops >20% body weight in a molt and these two went >30% for weight loss at the worst, dropping over a half pound in a mere few days at the time I intervened. Some of that rapid loss was dehydration-related, but not all. Feather mites are also ruled out with inspection by microscope.

Hobbit in particular got dangerously dehydrated to the point I was worried she could actually die, and I had to aggressively pipette water to her. These "shutdown" events lasted a few days and then concluded with a nearly full-body feather push including ditching some of the older "new" feathers. Now the chicken and the egg issue: is this final feather push a stress-induced molt from the metabolic issue, or a metabolic issue caused by the buildup of the big feather push? I have no way to know, but it's bad either way.

Both birds bounced back very rapidly once the new feathers were formed and just poking out, they started eating and drinking normally. I had to do a mix of keeping them inside 24/7 and keeping them in just at night based on ambient temps, trying to make sure they still got some social time with the flock when possible. Both are now putting weight back on slowly. Worms were definitely a complicating factor earlier, but I now really have to think there is just something genetic at hand here.

Here they are, still scratty with the new set of feathers coming in but no hen saddles needed anymore. Raven is the one on the bottom; full set of head feathers now, which is much better than her previous turkin-like look.

There is one other reason I suspect a strong genetic factor now. I have one other bird in which I have seen this kind of catastrophic metabolic issue during a molt, and she is from the same batch of "olive eggers" - she is just striped and lays dark brown speckled eggs rather than olive. And I wasn't thinking of her earlier because she actually did do her molt in the winter, it was just awful. In Feb this year, she did her first annual molt and had to be either tucked inside my jacket or sitting on a heat mat for several days while indoors at 68F. At the time, I attributed her issue to picking an extraordinarily dangerous time to be naked (my area saw max humidity -20F that month!). However, now I'm more suspicious of what was behind her metabolic issues indoors given two of her same-hatchery cohort have just done the same thing at much warmer temps.

Meanwhile, all of my other birds old enough to be molting are somewhere in the process, whether near the start or finishing up, and it's been pretty uneventful for them.

 

[NatJ]

Now the chicken and the egg issue: is this final feather push a stress-induced molt from the metabolic issue, or a metabolic issue caused by the buildup of the big feather push? I have no way to know, but it's bad either way.

That is a good question, and I do not know the answer for sure.

But what you described (not eating, weight loss) sounds like a recipe for forced molting (usually caused by the person withholding food, not the hen's choice.)

So I could easily believe the molting is the effect, and the rest of the issue is the cause.

Then again, considering all the time those birds have been molting, I could also believe that the long drawn out molting caused all the rest of the problems.

They are part of a breeding flock although obviously I have not hatched from these two since I don’t know what’s going on with them.

You said that months ago, but I'm thinking that was a wise choice on your part! Whatever is causing the trouble, you certainly don't want to breed more like that.

 

[DonyaQuick]

You said that months ago, but I'm thinking that was a wise choice on your part! Whatever is causing the trouble, you certainly don't want to breed more like that.

It's a shame, since I thought I was being pretty safe with overall health by getting birds that were fundamentally a cross, even if from a big hatchery. Although, I suppose I'm actually kind of lucky that these two and their barred "sister" I mentioned all lay eggs that are quite distinct and thefore will never get accidentally put into an incubator, being green and dark brown among a sea of light brown ones that are increasingly hard to tell apart.

But what you described (not eating, weight loss) sounds like a recipe for forced molting (usually caused by the person withholding food, not the hen's choice.)

Do you happen to know what the expected timeline is between the start or end of the stress event and the molt it induces? I'm just wondering if that's something I could use to add liklihood one way or the other. I saw a physical stress-induced molt in a different bird for completely unrelated reasons earlier in the year and I feel like there was a longer gap between the turning point in starting recovery and seeing feathers starting to get pushed out.

 

[NatJ]

Do you happen to know what the expected timeline is between the start or end of the stress event and the molt it induces? I'm just wondering if that's something I could use to add liklihood one way or the other. I saw a physical stress-induced molt in a different bird for completely unrelated reasons earlier in the year and I feel like there was a longer gap between the turning point in starting recovery and seeing feathers starting to get pushed out.

I don't really know, so I started poking around online...

I looked at the wikipedia article on forced molting:
https://en.wikipedia.org/wiki/Forced_molting

Then I checked some of the sources that were referenced in the wikipedia article.

There was a link to an online version of the book
"Poultry Husbandry" by Morley A. Jull, published in 1938
https://archive.org/details/poultryhusbandry00jull
That author discusses forced molting on page 325-326, and makes these statements about timing:
"The molting period usually requires from 15 to 23 days."
"The resting period starts after most of the feathers have been shed and continues for approximately 6 weeks."

Wikipedia also cited a paper titled "The effects of alternative forced-molting methods on the performance and egg quality of commercial layers."
https://www.scielo.br/j/rbca/a/TzxXfHCSxxdMrsCLwP9T57S/?lang=en
That study compared several different methods of force-molting chickens, including "fasting" for 14 days (might mean no food at all for that time?) and several restricted-calorie diets for various lengths of time.
It looks like they were targeting a weight loss of 25% over 28 days, and it says that "the birds in the treatments that reached 25% body weight loss before 28 days were fed ad libitum immediately after that weight loss was obtained." So they went more by the weight loss than by a certain number of days.
But I do not see anything about when the feathers are lost within that time, or how fast they grow back.

I don't know if that is enough to help you figure it out or not.

 

[DonyaQuick]

Well, these two hens are not out of the woods yet. Metabolic issues continue and I may yet lose both of them to it if I can't get it in check, since it's really bad this time. The past couple weeks, one gained weight rapidly above her normal range and the other is headed towards being emaciated - dropped way below her molting weight really fast. No signs of tapeworms this time although I will be doing fecal floats for both this evening. Both were healthy weights for their builds initially after their molts finished and these problems seem to have been brought on by a bout of abnormally warm and sunny weather that caused egg production to bump up in all my other hens like it would in spring (of course, it was temporary; it's now very cold again and so the egg rates are back to low winter levels). Starting to wonder if it's a thyroid thing...maybe hyper in one and hypo in the other. I was still on the fence about what caused what with the molts and weight loss before, but this new round strongly suggests some kind of underlying metabolic disorder as a root cause in both birds.

 

[DonyaQuick]

I honestly thought my next post in this thread would be reporting two dead birds. Miraculously though, they have both bounced almost completely back to normal. Well, perhaps it's not that miraculous...they have both been house chickens since I discovered the problems and I have very aggressively been monitoring and treating them to give them the best chance possible.

Fecal floats for both birds turned up nothing.

Hobbit is the one who gained weight rapidly and became sluggish. Her abdomen was large but didn't feel right for something like ascites, in part because her degree of abdominal swelling seemed to rapidly fluctuate. I no longer suspect purely thyroid issues for her after seeing things play out, although hypothyroid is still on my radar as a possible underlying situation. During her initial stay in the house she refused food and water and I had to make her drink water with a syringe (the side of the mouth method, not down the throat). After a few days, she laid a series of bizarre tiny eggs, one per day, that led me to conclude she had an ovarian cyst that must have later ruptured. The first tiny egg looked like a normal fairy egg on the outside, but it contained a massive blood clot - that's all that was in it, just solid red blood, nothing else. The second egg was a bowling pin shape and contained a similarly shaped and quite large piece of pink tissue wrapped in a little bit of albumen. The third egg contained a more amorphous piece of lumpy pink tissue and a small amount of albumen again. There was also a fourth egg, but she ate it so I didn't get to see what was in that one. No signs of lash material in any of the eggs. Based on the fact that these sizable tissue portions were clearly passed through the rest of the egg machinery in order to be wrapped in shell, I have to assume I was seeing shed ovarian tissue - maybe even a chunk of the ovary in the lumpy case. Unfortunately I didn't stop to take pictures of these cases. After these weird "eggs," Hobbit passed a very small amount of yolk material in her poop. Once that was out, her abdomen went back to normal and she made a sudden rebound. It took a few more days for her to return to normal eating and drinking but she is very close to back to normal now, although still on the low metabolism side; normally I would expect her to get too warm and start panting and have very hot feet/legs after sitting on my lap for extended periods of time but that no longer happens.

Raven should be a roughly 5 to 5.5lb hen and would join me daily for my morning coffee with chickens ritual, so I thought I had a good handle on her overall health. One day shortly after Hobbit fell ill, I picked Raven up and it felt like I picked up nothing - she was 3.4lbs and her backside was concave. Winter gloves perhaps make checking a bird more difficult but this deterioration she had was still very fast. All she needed to begin recovery was warmer temperatures and a steady supply of food. At first she completely refused to eat dry foods; I'm still not sure what led to that, because she's normally the exact opposite of a picky eater. She would eat as much mash as I would give her so that's what I did day after day. I had to break her food into frequent meals because she was ravenous to the point I was worried she could risk aspirating food if I didn't make her wait a bit for her crop to empty. She is currently back up to 4.6lbs and eating dry food again, although her water consumption was and still is more than twice what I would normally expect for a hen her size. She is a very active bird that runs around a lot and has always seemed to be one of my higher metabolism birds. The water consumption paired with the long time high metabolism is what makes me wonder about hyperthyroid.