A must-have for all chicken owners is the Chicken Health Handbook by Gail Damerow. Order your copy today at Meyer Hatchery - Chicken Health Handbook.
Sour crop is the term used to describe a condition that occurs in a chicken’s upper digestive tract when a yeast overgrowth occurs. Yeast that is normally found in the digestive tract of poultry can grow to an unbalanced level if the chicken’s immune system is otherwise compromised due to stress or other illness.
Candida albicans is the yeast species that typically causes sour crop. Signs of a chicken with a sour crop are a large, distended crop, breath that smells yeasty, and the crop feels fluid-filled or squishy when you gently squeeze it.
Treatment is not always successful, especially if you do not also determine and treat the underlying reason why a Candida overgrowth developed in the first place. Successful treatment is even less likely if the crop has been stretched beyond its capacity and has lost its elasticity.
You can try to empty the crop contents by gently massaging the crop and inverting the chicken’s head downward. Be aware that there is a risk that the chicken may inhale the crop contents as it regurgitates it. Invert the head for no more than 30 seconds at a time. Repeat two or three times a day until the crop no longer looks distended.
Using probiotics in the flock’s feed or water may help bring the crop microflora back into balance. Also, adding apple cider vinegar to the drinking water at a rate of 1 tablespoon per gallon of water may allow the good bacteria in the crop to out-compete the yeast.