Typically, a hen’s crop will become impacted by something the chicken has ingested. The blockages could be the result of the hen ingesting tough long grasses, sawdust, straw, hard grains or meat bones that get lodged in the crop. As chickens cannot chew, tough stems etc cannot be broken down before entering the crop.
Chickens may exhibit a large bulge in the crop area and also a sudden loss of weight. The bird may also jerk its neck around trying to dislodge the blockage. Additionally, the stuck items in the crop may begin to rot, resulting in a sour (sour crop) smell coming from the chicken’s beak.
If you examine the chicken, the crop will feel very full, as if it is full of dough. The best time to do this is first thing in the morning (before the chicken has had a chance to eat any food) as the crop should empty overnight.
Treatment in mild cases
It is important to treat an impacted crop quickly otherwise the bird will starve. In mild cases, the contents of the crop can be softened before emptying. Whilst this sounds difficult, it is in fact quite straight forward and usually does the trick in mild cases of impacted crop.
Holding the bird firmly pour a couple of teaspoons of olive oil down its throat and then massage the crop for about 5 minutes, to soften the contents. This is probably best done by two people. Then turn your chicken upside down with its head away from you and massage the contents out through the beak for a short while. Do this for only about 10 seconds at a time and then turn it back the right way so that it can breathe properly. If you are at all concerned about doing this you should take the bird to a poultry vet.
Treatment in serious Cases
In more serious cases, when the crop cannot be emptied easily, you will need to take your chicken to the vet. A vet will usually have to open the crop up to empty the contents and then stitch the bird back up.
Prevention is better than cure so try to ensure that all long grass is cut where the chickens forage and keep living areas free of foreign objects such as plastic or sharp objects that your birds could eat. Always make sure that water and grit are always available.