Pendulous crop is an abnormal condition in chickens where the crop becomes distended from its normal position, and fills with ingested feed and fluid. Chickens who are raised entirely on pelleted feed are more at risk of developing pendulous crop, as a result of modification in the gut flow due to poor gizzard development.
As soon as the bird starts to ingest different feed materials or larger volumes, the gizzard can't keep up, causing food to be constantly stored in the crop. The crop expands, stretching the muscles, losing the capacity to contract and empty, until it reaches a point where the damage is irreversible. There are several negative implications for when this occurs:
- The contents within the crop essentially get stuck, which will stagnate and potentially ferment. This leads to a condition known as sour crop.
- The chicken is not able to absorb all the nutrients and has an increased risk of dehydration.
There are several different causes of pendulous crop in chickens, including:
- Excessive water intake
- Defects in the crop itself
- Consumption of coarse fibrous feed
- Partial blockage of the proventriculus or gizzard, due to tumors, high parasite loads, or the presence of a foreign body.