how common is sour crop? will we eventually have to deal with it? or does it depend on the chicken?
It is not uncommon, as in rare, but it is not something you need to worry you are going to have a lot of if you watch what your birds have available to them. String, twine, straw, hay, long grass, whole corn can all be culprits. However, not all chickens will eat straw, most will just scratch and peck through it to get the seeds that didn't get harvested off. As some have said here, some chickens will eat hay, while others see it as a nesting material or litter. I would think straw would be preferable to hay for those. I have some birds that gorge themselves on grass when they are first let out on it.
Sour crop comes from the entrance to the gizzard gets blocked and food can't pass into it or the bird has gorged themselves on something long and stringy that binds up in their crop. The crop them becomes 'sour' because the feed they eat with it then begins to ferment.
The first thing I do is try to vomit out the mess in the crop. Sometimes if it is impacted with grass or straw, then you need some lubricant to assist in this, like olive or vegetable oil put directly down the throat into the crop. But all of this has to be done carefully so that the chicken doesn't aspirate it into their windpipe and starts another problem.
I have had some that if they just had a piece of corn or something like that, then stimulating the crop and vomitting the contents out have cleared it up. Others, I would then give them water with ACV only for 2-3 days, followed by active culture yogurt (can use Probios for horses) then some scrambled egg, then start reintroducing the feed but no scratch until it has all cleared up.
As I said, with my own birds, I can't recall any besides my Welsummers getting it. Why they would have it more than others, I don't know. I am certain it is something genetic if they are the only ones I have had to worry about or have found it with, and it has been with both males and females. Almost every case has been where they were eating a bunch of grass.
The first hen I had get it was very impacted and I couldn't get it to clear out. I did surgery to clean out all the grass and other stuff she had packed in there, but then her crop ruptured where I stitched her up and caused a secondary infection and I lost her.
With the first time, I believed it was whole corn that messed her up. I was feeding mash from the local mill and often would have whole grains in it, while everything else was dust. I switched to crumbles and the only ones I have had since are with grass in their crop too.
If you don't do something to resolve it when it presents itself, a bird will slowly starve, so just keep an eye out. You can tell they have it by a saggy, gassy bulbous crop.
