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What is Sour Crop in Chickens? How to Prevent & Treat It

Have you given much thought to your chicken’s crop? Probably not. You might know that the crop is an essential part of the digestive tract and that a chicken’s food is held there. However, you might not know that the crop can be infected, causing health problems for your unlucky chicken. What is sour crop in chickens and how do you prevent and treat it? You’re about to find out, so keep reading.

A Brief Lesson on the Chicken Digestive System

vet working on chicken farm

In order to understand the crop, you must first know about how the digestive system works and what’s included. Chickens are not like humans. They don’t have the same organs you do, and so it can sometimes be difficult to understand what is wrong with them.

A chicken’s digestive tract begins with their mouth. When they eat something, they swallow it without chewing, because chickens do not have teeth. The food travels from their mouth, to the esophagus and then down into the crop. Think of the crop as a pouch where the food is stored. Being that chickens are after prey, they needed to develop a way to hold their food until they were safe enough to settle in and let their body digest and process nutrients.

The food is then moved from the crop into the proventriculus, a small tube that connects to the gizzard. In the proventriculus, digestive enzymes are added to the food, beginning digestion. The gizzard is where the food is ground up into a paste.

The nutrients are then absorbed as the food continues on through the intestines, eventually ending up in the cloaca, where it is excreted as poop.

What is Sour Crop?

You now know that the crop is the food storage pouch. So what is sour crop?

Sour crop is an infection caused by Candida albicans, a form of yeast that is known to cause thrush in infants and babies. As in humans, candida is a naturally occurring bacteria. Usually, it is kept under control, but may become a problem when the bacteria “blooms.”

Normally, a chicken’s crop has a pH of around 5.5 to assist with the breakdown of food. Bacteria thrives in the crop, as it is integral to the digestive process. Should the acidity levels change, it can upset the bacteria population, causing candida to proliferate.

The crop walls are affected, causing thickening and dilation, which makes it harder for the food in the crop to pass through. Digestion problems are often the result. If a chicken cannot empty its crop, they may suffer and die.

What Causes Sour Crop?

There are a few causes that often lead to sour crop in chickens. Most of the causes can be easily avoided.


No, this has nothing to do with the worms that your chickens eat for snack. This is about parasitic worms that affect the digestive tract. One of the most common species of parasitic worm found in the crop is called the thread worm. It stays within the crop, stealing the nutrients from the food that your chicken consumes, leading to malnutrition. Worms can also lead to weight loss and a lack of appetite.

If you notice your chickens eating less and looking thin and haggard, it may be a sign that they are infested with worms.

Stringy Grass or Vegetables

In the spring, your chickens may be excited to nibble on so grass. Then they wind up swallowing a long blade, which is barely digestible even in smaller pieces. Long, stringy grass is notorious for balling up inside the crop and stalling the digestive process. In bantam breeds, a single piece of grass is often enough to impact the crop. Fibrous vegetables, like celery, can also cause similar issues.

Similarly, you do not want your chickens to eat anything moldy, as it will alter the pH level in the crop.

stringy grass

Infection and Antibiotics

If you are treating your chickens with antibiotics for an infection, the medicine may be to blame. Antibiotics often alter the delicate balance in the crop and may cause the bacteria in there to bloom.

It’s a vicious cycle, especially since you need to continue giving your chickens antibiotics to trump the primary infection.

Symptoms of Sour Crop

Chickens know that they are hunted out in the wild, and so they have adapted to hide their illnesses. For their owners, this can make determining if they are sick difficult. Don’t let this cause you any worry. Sour crop is actually easy to diagnose when you know what to look for. If you suspect that your chicken may have developed sour crop, separate them from the rest of the group. Leave the chicken without food or water overnight. In the morning, feel their chest, where the crop is located. You should feel nothing too concerning if the crop is normal. Anything that feels bloated, squishy, or soft means that the crop is not emptying out as it should.

The other sign is the smell. Sniff around your chicken’s beak. If the breath smells sour or a bit like fermentation, you know that they have sour crop without a doubt.

Other symptoms of sour crop include:

  • Weight loss
  • Lack of appetite
  • Lethargy
  • Diarrhea
  • Diminished egg production
  • Poor eggshell quality
  • Stomach gurgling
  • Sitting hunched over on the perch
  • Leaking fluid from the beak

Keep in mind that the symptoms above will only be noticeable after your chicken has struggled with sour crop for some time. You want to try to catch it before it reaches this point.

You can also watch this video, which talks about this topic in detail:

How to Treat Sour Crop in Chickens

One of the things that may shock you is that chickens cannot vomit. That means your chicken will not regurgitate any of the food stuck in their crop. Only a few options are left to you.

First, if you catch the sour crop early on, you may be able to massage the crop and assist in digestion. To do this, you must isolate the chicken and remove food and water for 12 hours. Gently massage the crop every couple of hours. Work the crop from top to bottom, adding just a little pressure.

After 12 hours, give your chicken some water but no food. During this time, you want to crop to relax a little. You want the crop to feel more relaxed to the touch after the fasting is done. If so, give your chicken some yogurt or scrambled eggs. Feed your chicken 3-4 small meals — nothing too fibrous or rich. Provide as much water as the chicken will drink.

What if My Chicken is Leaking Fluid From The Beak?

chicken with open beak

In the event that your chicken is emitting a foul-smelling liquid, it’s not vomit. It’s overflow. When this happens, you have two options: either take your bird to the vet for emergency care or massage the chicken more carefully. If you approach your chicken wrong when this is happening, it could cause them to draw fluid into their lungs, which is incredibly dangerous.

Instead of massaging top to bottom, you switch from bottom to top to help work the fluid out of the crop. Do this for no longer than 20 seconds. While doing so, tilt your chicken’s head towards the ground. They may expel a lot of fluid.

Epsom Salts for Sour Crop

epsom bath salt on wooden board

Another name for Epsom salt is magnesium sulfate, and it is one of the best remedies out there. Epsom salt can help cleanse the crop.

Dissolve about a teaspoon of Epsom salt into a cup of water and give it to your chicken 2-3 times throughout the day. It is recommended that you give it via syringe, as your chicken won’t likely drink the solution on its own.


In the worst case scenario, you are going to want to bring your chicken to the vet for prescription medication. Nystatin is an antifungal that can tackle even the most severe sour crop.

How to Prevent Sour Crop

Preventing sour crop is far easier than taking care of it once it has developed. Although you cannot guarantee 100% that your chickens won’t eat something they shouldn’t and get sour crop, using these preventative measures will make your life a little easier:

  • Provide clean drinking water with a little apple cider vinegar to assist with pH levels in the crop.
  • Limit your chicken’s intake of starches, including breads and pasta.
  • Give your chickens plenty of grit, such as oyster shells and gravel.
  • Keep your lawn from getting to unkempt so they don’t eat grass and weeds.
  • Provide your chickens with sugar-free probiotic yogurt once in a while to keep their gut microflora healthy and happy.
  • Mix in herbal additives, including parsley, oregano, garlic, and fennel.
  • Take your chickens into for routine veterinary checkups throughout the year.

Final Thoughts on Sour Crop

Sour crop can be a devastating condition that affects the digestive system. Once a chicken gets it, you will either need to provide continuous care or take the bird to the veterinarian for prescription medication. It is better to prevent sour crop from occurring by keep the grass from growing too long and keeping your chicken’s coop and run clean and free of dangerous debris. Hopefully, you will never have to deal with sour crop, but if you do, remember the advice in this article.