Flock health
Crop Problems in Chickens: Sour Crop, Impacted Crop and Pendulous Crop
Sour crop in chickens is a yeast infection of the crop, usually Candida albicans, that leaves it soft, doughy and sour-smelling; an impacted crop is one blocked by hard, fibrous material and feels firm "like a golf ball"; a pendulous crop is a stretched crop that hangs low and does not recover, because its supporting muscles and ligaments are damaged (University of Maryland EBR-60; Penn State; Merck Veterinary Manual). The quickest check for all of them is the same: feel the crop first thing in the morning, when a normal one is empty (Maryland EBR-60). This page gives no treatment, dosing or surgery steps: those belong with a veterinarian.
Short version: feel the crop before breakfast during each hen health check. Empty is normal. Full and hard points to impaction, soft with a sour smell to sour crop, a low-hanging bag to pendulous crop. Keep grass short, string out of reach, feed and water clean. Call a veterinarian if a crop stays full after fasting or keeps getting harder, and before giving any medicine (Maryland EBR-60; Penn State).
Jump to: How a normal crop works · Crop problems chart · Causes in more detail · Prevention checklist · When to call a vet
How a normal crop fills and empties
The crop is an out-pocketing of the esophagus that sits just outside the body cavity at the base of the neck (Jacob, Kentucky). Chickens have no teeth and swallow feed whole; the crop stores it and releases it slowly to the gizzard, where it is ground (Maryland EBR-60). The labeled chicken anatomy diagram shows where it sits.
- After eating: a full crop is easy to find as a small bulge at the base of the neck, in front of the chest, and gentle massage lets you feel the texture of the feed inside (Maryland EBR-60).
- Emptying: under normal circumstances the crop usually empties in 2–4 hours (Penn State).
- Morning: before the birds eat, a normal crop is empty and hard to find, and once found it moves around under your fingers; first thing in the morning is the best time to check (Maryland EBR-60).
- Where the crop is: just outside the body cavity at the base of the neck (Jacob, Kentucky).
- Morning: empty and hard to find, which is normal (Maryland EBR-60).
- After eating: a small bulge that usually empties in 2–4 hours (Penn State).
- Impacted: full in the morning and "hard like a golf ball" (Maryland EBR-60).
- Sour crop: soft, dough-like contents and foul-smelling fluid (Penn State).
- Pendulous: the crop hangs low at the front of the bird (Maryland EBR-60).
Crop problems chart: sour crop vs impacted vs pendulous crop
| Condition | How the crop feels and looks | Other signs | Common causes | When to call a vet |
|---|---|---|---|---|
| Normal | Small bulge after eating; empty and hard to find before the morning feed (Maryland) | — | — | No need |
| Impacted crop | Still full in the morning, firm and hard "like a golf ball," does not move with gentle massage (Maryland); contents feel firm and the crop does not empty (Penn State) | Reduced appetite, weight loss, depression (Penn State); a swollen crop can block the windpipe and suffocate the bird (Jacob) | Long grass, hay twine, plastic or thread (Penn State); newspaper, feathers, string (Maryland); gorging after a fast (Jacob); nervous system disease such as Marek's (Maryland) | If it is still full after an overnight fast, or lasts for days and gets harder; surgery may be needed (Maryland; Penn State) |
| Sour crop (crop mycosis, candidiasis) | Enlarged, soft and doughy with foul-smelling fluid (Penn State); sour smell; may show a fine white pseudo-membrane into the esophagus and mouth (Maryland) | Listlessness and loss of appetite may be the only signs (Merck) | Candida albicans yeast after long-term oral antibiotics; spoiled feed, slimy or unclean water; a pendulous or impacted crop; anything that weakens immunity (Maryland; Penn State; Merck) | Before using any antifungal: a vet confirms the cause and sets the dose (Maryland). Diagnosis uses crop fluid and fecal exams or tissue tests (Penn State; Merck) |
| Pendulous crop | Crop hangs low at the front of the bird (Maryland); grossly distended, with foul-smelling fluid, feed and litter (Merck) | Keeps eating but loses weight; may become emaciated (Maryland; Merck) | Not fully known; often binge eating, excess water, or lots of fibrous material such as grasses, rocks or sand; chicks brooded too hot drink too much (Maryland); erratic or excessive feed or water intake (Merck) | For a diagnosis and to discuss options: there is no cure, since the supporting muscles and ligaments are damaged (Maryland; Merck) |
| Crop worms (Capillaria) | Crop stasis: a crop that is slow to empty (Maryland) | Poor condition, weakness, emaciation, breathing difficulty, sometimes sudden death (Maryland) | Thread-like worms, more common in floor-raised birds; birds pick them up by eating earthworms (Maryland) | For diagnosis (Penn State uses fecal exams for Capillaria eggs) and any dewormer, which vets may prescribe off-label; eggs and meat are off-limits until the drug has cleared (Maryland). More on internal parasites |
Problems overlap: Maryland lists a pendulous or impacted crop among the causes of sour crop, and Penn State adds foreign bodies, tumors, Marek's disease and Capillaria worms to the causes of poor emptying. A crop that will not empty is a sign, not a diagnosis.
Causes worth knowing
- Pasture: impaction is more common in free-range birds, and birds without fresh greens over winter may overeat grass clippings; dry feed eaten after a fast swells once the bird drinks (Penn State).
- Sour crop is opportunistic: the yeast lives in healthy birds and causes disease when the normal gut flora is disrupted; young chicks are the most susceptible (Merck). It is not passed from bird to bird, but flockmates in the same conditions can get it (Maryland).
- Pendulous crop is permanent: a supportive "crop bra" helps only while worn (Maryland; Penn State), and Maryland says affected birds should not be used for breeding.
Prevention checklist
- Short grass: if birds have pasture access, keep grazing areas cut short (Penn State).
- Nothing stringy: keep runs clear of twine, thread and plastic (Penn State; Maryland).
- Grit: provide a source of grit (Penn State); how grit fits into the ration is on feeding laying hens.
- Regular, clean feed: avoid spoiled feed (Maryland; Penn State) and long gaps without feed followed by gorging (Jacob). For treats and scraps, see what chickens can eat.
- Clean water: waterers free of slime (Penn State; Maryland); cleaning tips on water for chickens.
- Antibiotics only when needed: Maryland and Merck both point to unnecessary or prolonged antimicrobial use as a trigger for sour crop.
- Brooder heat: overheated chicks drink too much, which Maryland links to pendulous crop; temperatures by week are on chick care for the first 8 weeks.
- Dry ground: good husbandry and dry, well-drained soil help prevent crop worms (Maryland).
When to call a vet
- Rule out a late meal first. Maryland warns against over-diagnosing impaction: separate the bird with water but no feed and see whether the crop empties. A crop still full after fasting suggests something indigestible.
- A crop that stays full or gets harder. Maryland: if an impaction lasts for days and becomes harder, surgery may be needed, so "contact your veterinarian before it's too late."
- Handle gently. Aggressive massage of an enlarged crop full of fluid can cause aspiration pneumonia (Maryland).
- Before any medicine. Maryland says to consult a veterinarian before using antifungal or antiparasitic drugs and to follow their dosing; it warns that copper sulfate is toxic in overdose. Any drug leaves residues in eggs, and off-label use needs a veterinarian's prescription (Kansas State, FARAD).
- Find a vet early. Federal rules require a veterinarian-client relationship before prescriptions can be written, so make the connection before birds are sick; county Extension offices can help find one (UW–Madison).
HenClass summarizes extension and veterinary guidance and gives no veterinary advice, doses or procedures.
Sources
- University of Maryland Extension — Common Crop Issues in Backyard Chickens (EBR-60, Moyle, Ghanem and Perdue, 2021, updated 2024)
- Penn State Extension — Crop Disorders of Chickens I: Crop Impaction (January 2024, republished by The Poultry Site)
- Penn State Extension — Crop Disorders of Chickens II: Ingluvitis (January 2024, republished by The Poultry Site)
- Merck Veterinary Manual (Jenny Nicholds) — Candidiasis in Poultry (reviewed April 2023, updated September 2024)
- Merck Veterinary Manual (Eric Gonder) — Pendulous Crop in Poultry (reviewed March 2023, updated September 2024)
- Jacquie Jacob, University of Kentucky (Poultry Extension) — Avian Digestive System
- Kansas State University — Veterinary pharmacologist warns that eggs from backyard chickens pose potential consumption problems (FARAD, September 2014)
- University of Wisconsin–Madison Extension — Finding a Veterinarian for your Chickens (Ronald Kean)