Sour Cop in Chickens: Cause, Treatment and Prevention

As caretaker over a flock of hens (and maybe some roosters), it is so important to keep tabs on each one. Any signs of illness or disease can quickly spread to the entire flock, making a visit to the vet very expensive, or nearly impossible. Luckily, sour crop is not one of those diseases that can wreak havoc on your hens, unless of course, you catch it too late.

In this short blog post, we will help you gain a better understanding of sour crop. First, we will briefly discuss the parts of a chicken, then explain what sour crop is and how to notice it. Next, we will talk about what causes sour and the steps you can take to prevent it from happening in the future. Finally, we will briefly discuss various treatment options.

Anatomy of a Chicken

Just like in humans, the chicken’s digestive system begins at the mouth. From there, food passes down the esophagus to the crop, then eventually to the gizzard, through the intestine, and then out through the cloaca. If any part of the digestive tract is blocked, the rest of the system will suffer.

The “crop” in a chicken is the part of the body that receives food first. It is sort of like a little holding tank, which is located just to the right of the chicken’s breast bone. The chicken will store her food here while she grazes.

If a chicken has just finished eating, it will feel firm to the touch. This is very common in the evening, as the chicken will store its food in the crop in order to digest it throughout the night.

sour crop

The crop’s condition is a great indicator of the health of your chicken. If the crop is empty at night, especially for more than one evening in a row, your chicken may be sick and is not eating.

On the other hand, if the crop is still full the morning of the next day, then the chicken has not passed the food out of the crop. This could indicate a problem with the digestive tract, and if left untreated, a build-up of a fungus in the crop, called Candida albicans yeast, could occur.

This build-up of yeast is what is known as a sour crop. One final way to diagnose it yourself is to investigate as the name implies: if you smell a sour odor coming from your chicken’s mouth, and the crop is full when it should not be, chances are, your chicken has a sour crop.

Candida albicans is a common bacterial strain that can naturally occur in the chicken’s gut. Just like our digestive system, the chicken’s tract is home to a whole host of healthy and beneficial bacteria that help everything run smoothly.

It is only when a build-up of the bad bacteria occurs, that a problem may arise. Unfortunately, Candida albicans is not one of the beneficial bacteria strains.

Learn more about chicken anatomy.

Signs and Symptoms

Like we mentioned previously, one of the biggest signs of sour crop is a swollen crop area. You will want to gently feel the crop and notice whether or not it is squishy to the touch. Listen for gas moving around. The gas is a natural side effect of the food that is fermenting in the crop. This is not something you want to hear!

Along with a foul odor, these are the things to notice when your chicken already has a sour crop. However, there are things to notice early on, before the crop has a chance to develop into the sour crop.

If you are keeping regular tabs on your hens, and you know how each one behaves on any given day, then you can more easily determine when a hen might be off. Things to look for include:

  • Drowsiness
  • Quiet and keeps to herself
  • Diarrhea
  • Loss of appetite
  • Weight loss

If your bird is not eating, she will be more tired. If she is tired, she will stay away from the active hens because she only has enough energy to keep to herself. She may develop diarrhea as a result of the bacteria in her gut beginning to become diarrhea. And then, much later on, and hopefully you have already noticed the swollen crop, she will begin losing weight.


sour crop chicken

Sour crop can be caused by a number of different things. Your chicken might just naturally empty her crop a little more slowly. Over time, this may lead to routine sour crops.

Sour crop can also occur if a chicken is recovering from another sickness, which required antibiotics. Antibiotics disrupt the entire digestive system, and while the chicken is recovering her natural gut flora, some unhelpful bacteria may get out of hand.

Infections and diseases left untreated can also cause sour crop. When the system is already weak, other problems can more easily arise. Chickens can also get worms, which are very destructive to their bodies.

Injuries can also cause a sour crop, and even something much worse.

Most commonly, however, your chicken might just be eating moldy food.

Preventing Sour Crop

One of the first things to do in order to prevent sour crop is to be aware of how your chickens normally behave and ensure that they are living in a safe, healthy environment with all of the necessary things in order to live a quality life.

Your chickens need:

  • Fresh, clean food and water
  • Access to grit (easily obtained by putting in with their food)
  • A source of probiotics

You can add apple cider vinegar to their water, which is a great source of probiotics, and also helps to keep the water cleaner for longer.

You also need to be aware of their habits. Do they like to scavenge? Do they typically fill up on the food that you provide for them?

If they like to scavenge, be sure that their scavenging areas are free of debris and garbage. Chickens might accidentally ingest harmful items out of sheer curiosity, which might block their digestive tract. Regularly cut low any tough grasses and grains.

If you have a garden, plant some helpful herbs like cayenne, chamomile, clover, and ginger, which are all beneficial to a chicken’s gut flora. Cayenne is especially beneficial in inhibiting the growth of bad bacteria.

if you feed your chickens table scraps, be sure to go extra light on processed carbohydrates (or omit them altogether), and limit their intake of starchy vegetables. Rather, increase their intake of pumpkin seeds, garlic, and catnip, and keep their worm intake relatively low.

Finally, taking your birds to the vet on a routine basis will help prevent anything from developing in the longer term.

Treatment Options

There are many home treatment options for sour crop. You can try to dislodge your chickens’ crop on your own (and with the help of a friend). Try by first massaging your chicken’s crop up and down, very gently as it is probably very sore and painful. Then, very carefully, so as not to asphyxiate the chicken, you can administer olive oil with a dropper.

If the lodged food is not coming out through the mouth, you can try it again, but this time, turn your chicken upside down. You may have to do this a couple times, but when you finally feel as if you have gotten as much out as possible, take a break and let the chicken rest. If she is not too upset, try feeding her a little probiotic yogurt.

There are many treatment options, including natural home remedies.

But never shy away from your chicken’s vet. They can confirm for sure that your chicken has sour crop, and then provide the necessary treatment in order to ensure a speedy, healthy, and humane recovery.


Now that you know a little more about the sour crop, you can hopefully take additional precautions. In order to prevent your whole flock from getting it, make sure that they have safe grazing areas.

Clean their water tub regularly, and ensure that they have a steady and reliable source of fresh water. Add probiotics like yogurt to their food and water, and treat them to nuts rather than worms.

Always get a good visual of your hens in the morning and at night, and look for any swelling to the right of the breast bone. And if your chicken does get sour crop, immediately start treating your chicken either by massaging it yourself, adding healthy doses of additional probiotics like apple cider vinegar, or bringing your hen to the vet.

If you do not tend to sour crop, it will get worse and will eventually kill your chicken. Yet, this is not something to worry about, so long as you are attentive to the needs of your flock, and treat any symptoms as they arise.

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