Candida albicans is an opportunistic, yeast-like fungus. It can be the primary or secondary cause of crop-infections (sour crop) in chickens and other birds.
C. albicans is a normal part of the gastrointestinal microflora of healthy chickens (and humans). However, given certain circumstances which enable its overgrowth, it can disrupt the chicken's mucosal barriers leading to infection and disease. C. albicans is also commonly found in the skin and urogenital tract of humans. It is what frequently causes yeast infections in woman.
C. albicans overgrowth can occur from treating poultry with antibiotics, as it results in the loss of normal bacterial flora and an increase in the number of candida organisms within the chicken's digestive tract. Young chicks and immunocompromised poultry are most susceptible to overgrowth.