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Crop Impaction

Other Names: Impacted Crop, Crop Binding

Crop impactions occur when there is an interference with the normal functioning of the crop, resulting in a partial or complete blockage of food passage. The chicken's crop is like a temporary storage pouch. It is an out-pocketing of the esophagus and is located just outside the body cavity in the neck region. It is where the initial stages of digestion occurs in chickens. Sometimes you can feel the contents and whether it is full or empty. When the crop is impacted, the contents will feel full.

Crop impactions may occur due to the presence of indigestible foreign substances, such as:
  • String (crafts, hay bale twine, artificial grass, carpets, etc.)
  • Long blades of grass (ornamental or pasture/yard variety)
  • Feathers
  • Skins from certain fruits (banana, persimmons, etc.)
  • Bedding or ground litter (straw, wood chips, mulch, shavings)
  • Misc plastic or metal objects
Crop impactions can also occur secondary if birds are having muscular contraction issues, since these contractions are what controls the normal movement of food through the crop. Some forms of Marek's disease are known to cause muscular contraction issues, specifically related to crop functioning.

Sour crop often occurs as a secondary complication in chickens with crop impactions.

Treatment for Crop Impactions

Treatment depends on the cause, the health status of the bird (why early discovery of this condition is ideal), and severity of the impaction. Trauma to the gastrointestinal tract often occurs as a secondary result of ingestion of foreign objects. For example, there were several cases where chickens who had ingested baling net wrap lost their tongues from ischemic necrosis. Others developed secondary septicemia and airsacculitis. When treatment is delayed, the condition rapidly worsens and leads to secondary infections, starvation, dehydration, and death.

Clinical Signs

Enlarged crop
Crop fails to empty
Reduced number of droppings
Smaller droppings then normal
Reduced or lack of appetite
Increased thirst
Twisting neck side to side
Open-mouth breathing
Foul odor from mouth
Smelly watery vomit
Pasted vent


  • History
  • Clinical signs
  • Physical exam

Reported Cases

  • Case 1: Crop and gizzard impaction from ingestion of baling twine in a Chickens A small commercial flock of day-old laying hen pullets was placed into 2 barns in floor pens bedded with straw, which contained pieces of baling twine. Some of the hens started displaying signs of labored, open mouth breathing, increased respriatory effort, depression, and ruffled feathers. Some birds had a small volume of clear fluid dripping from their beaks. They were also underweight and in fair to poor body condition. At postmortem examination, 1- to 3-cm long segments of linearly twisted bale net wrap were found in the upper gastrointestinal tract of all the birds. Three birds had 2 cm diameter balls of net wrap filling the crop with string extending up the esophagus, and in 4 birds, the string looped around the base of the tongue. Two birds were missing their tongues entirely, likely from ischemic necrosis, and in 1 of these birds, the string was wrapped around the larynx. All 7 chickens had intussusception of the proventriculus into the gizzard and 2 birds also had 2- to 3-cm diameter balls of net wrap in the gizzard. The mucosa of the proventriculus was markedly reddened, and ulcerated and a large amount of yellow cloudy exudate was loosely adherent to the proventricular and gizzard mucosa. Three birds had cloudy air-sacs indicating airsacculitis. Trauma to the upper gastrointestinal tract from the net wrap caused significant necrosis and inflammation of mucosal surfaces and loss of organs (i.e., tongue), serving as portals of entry for bacteria which would explain the lesions of secondary septicemia seen in the liver, spleen, and air sacs. The increased respiratory effort and open-mouth breathing could have also contributed to the development of the airsacculitis. The overall poor body condition and inability or reluctance of birds to prehend feed would have contributed to the mild to moderate bursal lymphoid depletion Ref

  • Case 2: Phytobezoar causing crop blockage in a Silkie bantam A Silkie bantam was brought to see the vet. The owners had noticed that the crop was larger than normal, but didn’t realize it wasn’t functioning properly until the bird had lost a noticeable amount of weight and reduced appetite. Physical exam revealed the crop was large and pendulous with a bulky, pliable mass within it, which had developed over a period of time. Initial treatment consisted of crop lavage and massaging of the crop, while the bird was receiving medication for a secondary bacterial and yeast infection. However, despite treatment, the mass within the crop would not resolve, and perpetuated secondary ingluvitis (inflammation of the crop). The mass was eventually removed via surgical intervention (an ingluviotomy). The mass that was causing the crop blockage was a phytobezoar, composed of a large fibrous mass of grass. The surgery was a success, however, the chicken required prolonged medical treatment due to a pendulous crop and secondary yeast and bacteria. A crop bra helped resolve it. Ref


Supportive careIsolate the bird from the flock and place in a safe, comfortable, warm location (your own chicken "intensive care unit") with easy access to water and food. Limit stress. Call your veterinarian.
Gentle messageGently message the chicken's crop.
Crop surgeryONLY performed by your veterinarian. NEVER attempt this surgery (or any surgery) on your chicken yourself. It's extremely inhumane and illegal. Chickens can feel pain they just don't outwardly show it because they are prey animals.



  • Provide birds free access to grit
  • Keep the grass mowed regularly, and make sure to remove any grass clippings and prevent the birds from accessing.
  • Always provide birds with plenty of fresh, clean water to drink.
  • Do not allow chickens access to any objects such as metal, plastic, strings, etc. even feathers which could be hazardous.
  • Do not allow chickens access to composts.


Outlook is good if treated early, as soon as symptoms are noticed.

Scientific References

Good Overviews


Risk Factors

  • Allowing chickens access to grass clippings.
  • Feeding dried oatmeal and soybeans, as they swell when they absorb water, which can impact the crop.
  • Feeding chickens a poor quality diet, making them crave ingestion of materials they wouldn't normally eat.
  • Leaving potentially hazardous objects where chickens can access them.
  • Chickens who did not receive the Marek's disease vaccine.