What is Candida?
Candida albicans is a common environmental yeast that can infect the digestive tracts of birds. It is a common cause of 'sour crop' or a crop infection, scientifically referred to as ingluvitis. Candida is more common in young birds. It may be spread from an adult bird feeding a young one, from being housed in a contaminated environment, drinking contaminated water, or eating contaminated hand-feeding formulas.
"It is a common cause of 'sour crop' or a crop infection, scientifically referred to as ingluvitis."
People with yeast infections in their mouths (thrush) have Candida. Candida can be a primary or secondary cause of crop infections. Candida, in small numbers, is usually considered a normal resident of a bird's oral cavity and digestive tract. A disruption or imbalance of normal bacterial populations in the digestive tract may lead to a secondary overgrowth of Candida. Excessive sugar or carbohydrates in the diet may contribute to Candida overgrowth, as yeast and fungal organisms grow well in high-sugar environments.
Often, other diseases compromise a bird's immune system and predispose the bird to secondary Candida infection (candidiasis). Steroid use, long-term antibiotic use, excessive stress, poor husbandry and hygiene, viral infections, and other chronic infections can all cause immune suppression and lead to secondary candidiasis.
In its advanced stages, Candida can affect a bird systemically, as it goes outside the gastrointestinal tract and invades the rest of the body; this is rare. With a systemic infection, it can be found in the blood, certain body organs, and bone marrow.
How do I know if my bird is infected with Candida?
Common clinical signs include lethargy, fluffed feathers, little to no appetite, vomiting or regurgitation, delayed crop emptying, a distended crop full of mucus, and occasionally a crop impacted with dry food, mucus, or other debris. Your avian veterinarian will start with a complete history, body weight, and physical examination. Since the clinical signs of candidiasis occur with many other diseases and are not specific to candidiasis, your veterinarian will likely advise a series of diagnostic tests to determine the exact cause of the disease.
How is candidiasis diagnosed?
Candidiasis is diagnosed by fungal culture and/or cytology (microscopic analysis) of fluid from either the crop or feces. A Gram’s stain is used to stain the fluid from the crop or fecal material to identify the organisms on a microscope slide. Since Brewer's yeast may be added to hand-feeding formulas and may be present in many baked goods, specific fungal culturing is recommended for differentiation, as Brewer's yeast and Candida can look similar under the microscope. If your bird had eaten baked goods or other yeast-containing foods during the day before the sample was taken and she is not severely ill, your veterinarian might suggest withholding all yeast-containing foods for a few days before rechecking a sample under the microscope. Severely affected birds should be treated regardless of whether they’ve eaten yeast-containing products.
"Severely affected birds should be treated regardless of whether they’ve eaten yeast-containing products."
The quality of the sample is essential. If a sample does not demonstrate yeast, especially if your bird is sick, it may be that she is not suffering from a Candida infection but some other illness. Further testing will be necessary to pinpoint the disease that is causing her illness.
It is common for candidiasis to develop secondary to other disease processes, so it will be necessary for other tests to be performed to determine whether there are other problems predisposing your bird to secondary infection. Early diagnosis generally leads to faster resolution of underlying problems.
Can my bird be treated?
Yes, once diagnosed, Candida is treated with antifungal medications. There are several medications available. In addition to treating candidiasis, your veterinarian should diagnose and treat all predisposing factors or diseases.
Good hygiene, a clean environment, and fresh food and water are essential in managing this problem and maintaining your bird's health. Correcting dietary imbalances will also aid in your bird’s recovery.
If your bird is diagnosed with candidiasis, follow your veterinarian’s recommendations in administering prescribed medications and ensuring your pet’s environment is adequately disinfected.