Causes

• When a chicken is eating too much food at a time, or rough food such as straw or hay that doesn't pass well, the food can get jammed in the crop. Chickens often overeat when they are young and growing. Eating too much without drinking can be another cause of an impacted crop.
  
  

Physical Signs

• An impacted crop will often be visible to the naked eye, bulging out of the chicken's body. You will see a large lump or ball sticking out of the chicken's chest. When you touch the area it will be hard, and the chicken is going to be clearly uncomfortable. There may also be a foul smell coming from the chicken.
  
  

Behavioral Symptoms

• A chicken will act oddly when it has an impacted crop. It will not eat or drink, and will look ill. A chicken with an impacted crop will often act like it is choking, or jerk its neck in different directions in an attempt to dislodge the jammed food. The chicken may also have difficulty breathing and appear in distress.
  
  

Cures

• If you think your chicken has an impacted crop, take it to a veterinarian right away. Attempting to remove the impaction on your own can be dangerous and even fatal to the chicken.