Identity

An opportunistic fungal disease of the upper GI tract caused by the dimorphic yeast Candida albicans. Triggered by antibiotic overuse or Vitamin A deficiency, it invades the mucosal epithelium of the crop, causing hyperplastic "Turkish towel" lesions.

Overview

Candidiasis is a moderate-priority opportunistic pathogen. Candida albicans is a normal GI inhabitant that transitions to a pathogenic tissue-invasive hyphal form when host defenses are compromised—typically due to prolonged broad-spectrum antibiotic therapy or Vitamin A deficiency. It targets the upper digestive system (crop, esophagus), forming characteristic white, cheesy plaques. Management involves withdrawing broad-spectrum antibiotics and treating with oral copper sulfate or feed-additive nystatin.

Structured Facts

Classification

Fungal > Infectious Pathogen

Epidemiology

• Severity: Low to Moderate
• Affected Species: Poultry
• Affected Age: Young chicks < 6 weeks and mature laying hens
• Transmission: Horizontal via ingestion of contaminated feed or water
• Mortality: < 5% (uncomplicated)
• Morbidity: 10% to 30% in compromised flocks
• Economic Importance: Low

Clinical Signs

• Early/Intermediate: Stunted growth, lethargy, listless appearance
• Advanced: Distended, flaccid crop containing sour-smelling fluid; targets Upper Digestive (Crop, Esophagus, Proventriculus)
• Postmortem Findings: Circular, raised, white-to-gray, velvety/cheesy pseudomembranous plaques resembling a "Turkish towel" or curdled milk in the crop/esophagus.

Diagnosis

• Field Diagnosis: Flaccid sour crop with internal white plaques
• Laboratory Tests: 10% KOH skin scrapings/mucosal smears (showing pseudohyphae and blastospores), Isolation on Sabouraud dextrose agar (creamy white yeast colonies)
• Differential Diagnosis: Fowl Pox (Diphtheritic/wet form), Vitamin A deficiency

Treatment

• Immediate Actions: Cease prolonged broad-spectrum antibiotics
• Supportive Care: Vitamin A supplementation
• Medicines: Copper sulfate (drinking water), Nystatin (feed additive)

Prevention

• Vaccination: None exist
• Biosecurity: Mitigated by standard Biosecurity Protocols, high sanitation in drinking systems
• Farm Management: Avoid indiscriminate use of antibiotics, ensure adequate Vitamin A nutrition

Quantitative Data

• Morbidity Rate: 10% to 30%
• Mortality Rate: < 5%
• Target Age: < 6 weeks and mature hens
• Copper Sulfate Dosage: 1:2000 dilution in water
• Nystatin Dosage: 100 g/ton in feed

Relationships

• Vaccines: None
• Medicines: Copper Sulfate, Nystatin
• Predisposing Factors: Broad-spectrum antibiotics, Vitamin A deficiency, Immunosuppressive diseases