Crop problems, and the three things people call sour crop

The morning check

Everything on this page depends on one habit. A full crop is normal — the publication notes that when full “it is visible as a small protrusion at the base of the neck in front of the chest.” A crop that is still full first thing in the morning, after a night without food, is not normal. That is the whole diagnostic, and it is why the check has to happen before the flock eats.

Impacted crop

The published cause is blunt: “eating large amounts of poorly digestible materials like newspapers, grass, feathers, string, plastic or other indigestible material.” Long grass is the one that catches backyard keepers out, because it looks like the most natural food in the world.

The published signs are physical. The crop stays full despite an overnight fast, and “if you palpate the crop, it will feel hard like a golf ball. You will not be able to move the crop around when you massage it.”

Treatment as published: isolate the bird with water but no feed at first, “continue to provide lots of water and gently massage the crop to help move the material through the digestive track.” If the impaction persists for days and hardens, “surgical intervention might be necessary” — contact a veterinarian.

Sour crop

A different thing entirely: “a yeast infection caused by Candida albicans”, and “most easily identified by the ‘sour’ smell it emits.” It can extend up into the mouth and “appear as a fine white pseudo-membrane.”

The causes are the useful part, because most of them are husbandry:

• Long courses of oral antibiotics. The publication names “long-term administration (1-2 weeks) of oral antibiotics, which affects the microflora of the upper digestive tract and causes yeast overgrowth.”
• Bad or spoiled feed. Which is a storage problem — feed kept in its paper sack in a damp shed is the usual route.
• “Slimy or unclean water, and watering systems that lack proper hygiene.” An open drinker with a biofilm in it is the most common version of this in a backyard flock.
• An existing impacted or pendulous crop, or anything that leaves a bird immunocompromised.

On treatment the publication names an antifungal approach and a flush, and is careful about one of them. Copper sulfate at a 1:2000 dilution in drinking water “is commonly used to treat and prevent fungal infections in poultry” — with the explicit warning that “copper sulfate overdose can be toxic for the birds” and that veterinary dosing guidance should be followed carefully. The simpler measure is a flush: “one teaspoon” of epsom salts in a cup of water, and “treatment is most effective when applied to an empty crop, so it is best to apply it early in the morning.”

Pendulous crop, and the honest part

“A pendulous crop hangs down in the front of the bird.” Affected birds keep eating but “lose weight and eventually become emaciated and may die”, because the crop cannot empty properly.

There is no treatment. The publication is unambiguous: no recovery is possible because “the muscles and ligaments have been damaged.” What exists is management — a “crop bra”, described as “a type of bandage that gently places pressure on the crop to help the contents empty into the stomach”, which “must be worn continually, as the crop will revert to the pendulous condition if the crop bra is removed.”

Two published notes matter for anyone deciding what to do. The condition “frequently develops after binge eating, excessive water intake, or consumption of large amounts of fibrous or indigestible material like grasses, rocks or sand”, and high brooding temperatures can trigger it because chicks “drink excessive amounts of water” — which is one more reason the brooder schedule is worth following. And it is heritable: “do not breed affected birds, as the condition can pass from generation to generation.”

What prevents all three

• Grit, free-choice. The gizzard cannot grind without it, and two of the three conditions start with material that did not get ground.
• Clean water, in a system that stays clean. “Slimy or unclean water” is named directly. A closed nipple system is harder to foul than an open pan — the waterer page covers the trade.
• Feed that has not spoiled. Which is a container, not a habit.
• No long grass clippings. The single most common backyard route into an impacted crop, and the one that feels like a kindness.