The advice hub Impacted Crop
The crop is a part of the oesophagus (food pipe) where the initial stages of digestion can occur. The crop is found at the base of the neck where you can sometimes feel the contents whether they are food, grit or water.
There are two common conditions of the crop: crop impaction and sour crop.
Crop impaction is where there is a problem with either the crop or the proventriculus (the stomach) where food fails to move from the crop to the stomach. There are two potential causes for this obstruction, either there is a foreign body which is blocking the passage of food such as string/plastic or long grass or the second possible cause can occur when the normal muscular contractions fail and movement of food is prevented from passing into the digestive system. Such causes can be problems with the nervous system which controls the muscular contractions; one such condition is Marek’s disease.
These birds present as being depressed with little or no appetite, and have a firm impacted crop.
The treatment can involve giving the bird supportive care such as fluids and hoping that the problem resolves itself but ideally surgery under a local anaesthetic to remove the offending material followed by washing the inside of the crop with sterile saline is recommended.
If your chicken has an enlarged crop it is important to ensure it has not recently eaten as after feeding, chickens often have an enlarged crop which shrinks back down as the food is digested. If you think your chicken has an impaction, monitor the size of its crop over several hours to establish if it is impacted.
If the obstruction is not caused by a foreign body but instead by motility problems, then even with surgery the condition can reoccur.
Prevention is as always much better than the cure. Prevent your chickens from accessing foreign materials such as string/plastic and your birds are not given access to very long grass. It is important that adequate insoluble grit is provided for your birds to help digest feed and grass.