Turkey Candidiasis (Sour Crop): Crop Yeast Infection in Turkeys

Turkey candidiasis is a fungal disease of the upper digestive tract caused by Candida yeast, most commonly Candida albicans. In turkeys, it often affects the crop, but lesions can also involve the mouth and esophagus. You may hear it called sour crop, thrush, or crop mycosis.

Candida is not always an outside invader. Small amounts can live in the digestive tract of healthy birds. Trouble starts when the normal balance of microbes is disrupted. That is why candidiasis is considered an opportunistic infection rather than a disease that appears out of nowhere.

In affected turkeys, the crop lining can become thickened and inflamed, with white, raised plaques or pseudomembranes. Some birds only seem quiet and off feed. Others develop obvious crop problems, poor growth, dehydration, or weight loss. Young poults are usually at the highest risk.

For pet parents and small-flock keepers, the key point is this: sour crop is often a sign that something else changed first, such as antibiotics, dirty waterers, poor nutrition, or another illness. Treating the yeast matters, but finding the underlying trigger matters too.

Candida yeast usually takes advantage of a disrupted digestive environment. In poultry, candidiasis commonly develops after therapeutic antibiotic use, which can reduce the normal bacteria that help keep yeast in check. Once that balance shifts, Candida can overgrow and irritate the crop and upper digestive tract.

Other important risk factors include unsanitary drinking equipment, contaminated feed or water, malnutrition, and vitamin A deficiency. Heavy parasite burdens and general stress can also make a turkey more vulnerable. Young poults are especially susceptible because their systems are less resilient and management problems affect them faster.

In backyard or small-farm settings, sour crop may also follow periods of poor intake, dehydration, overcrowding, or another illness that slows normal crop emptying. A turkey that is already weak can develop secondary yeast overgrowth more easily.

Because candidiasis is often secondary, your vet will usually think beyond the yeast itself. The goal is not only to reduce fungal overgrowth, but also to correct the husbandry, nutrition, medication history, or underlying disease that allowed it to happen.

Diagnosis starts with a careful history and physical exam. Your vet may ask about recent antibiotic use, age of the birds, sanitation, feed changes, growth rate, and whether multiple turkeys are affected. On exam, they may look for a delayed-emptying crop, dehydration, poor body condition, and white plaques in the mouth.

In live birds, your vet may collect crop contents, oral material, or feces for cytology. Under the microscope, yeast and inflammatory changes can support the diagnosis. In some cases, a flock veterinarian may recommend submitting a deceased bird for necropsy so the crop, mouth, and esophagus can be examined directly.

A very important detail is that culture alone is not enough. Candida can be part of the normal digestive flora in healthy birds, so finding it on culture does not automatically prove disease. More definitive diagnosis comes from seeing tissue invasion, often through histopathology showing pseudohyphae and blastospores in affected tissue.

Your vet may also look for other causes of poor growth, regurgitation, or crop dysfunction. That can include checking for parasites, nutritional problems, bacterial disease, or management issues. This broader approach helps match treatment to the real problem, not only the yeast.

Prevention focuses on keeping the crop and upper digestive tract in balance. Start with clean waterers and feeders, fresh feed, dry bedding, and good brooder or housing hygiene. Candida problems are more likely when birds are exposed to dirty drinking equipment or damp, contaminated conditions.

Use antibiotics only under veterinary guidance. Because candidiasis often follows disruption of normal flora, unnecessary or prolonged antibiotic use can raise risk. Good nutrition also matters. Turkeys need a balanced ration appropriate for age and production stage, and your vet may consider nutritional deficiencies, including vitamin A deficiency, if recurrent problems occur.

Young poults deserve extra attention. Watch for poor growth, reduced feed intake, or birds that seem slower and quieter than the rest. Early intervention can prevent a mild crop problem from becoming a larger flock issue.

If one turkey develops sour crop, review the whole setup. Clean and disinfect equipment, check feed storage for spoilage, reduce crowding and stress where possible, and ask your vet whether any flock-level testing or management changes make sense. Prevention is usually a mix of sanitation, nutrition, careful medication use, and fast response to early signs.