Crop Infections in Birds
Crop infections are common in pet birds, especially baby birds that are being hand fed. While not usually fatal if treated early, crop infections can be serious and result in a complete loss of appetite.
What is the crop?
"The crop is a muscular pouch located in a bird's neck."
The crop is a muscular pouch located in a bird's neck above the top of the chest or sternum. It is simply an enlargement of the esophagus in this location. The crop functions as a storage place for food. Adult birds actually produce crop milk from the crop. Crop milk is a secretion of the cells lining the crop, and is used to feed newly hatched birds. While present in most pet birds, not all birds have a crop.
What are some of the causes of crop infections?
"Sour crop is a term used to denote any infection in the crop."
The crop, being part of the digestive tract, can become infected by many of the same things that infect other areas of the gastrointestinal tract. Sour crop is a term used to denote any infection in the crop. The infection causes the crop to "shut down", and the food contents in the crop become sour. Crop infections can be caused by bacteria and sometimes yeast, especially Candida species. Trichomonas, a protozoal organism, causes crop infections that may be difficult to diagnose and this infection is often treated based on clinical suspicion. The virus that causes proventricular dilatation often also affects the crop. Other crop problems that can occur include crop burns (from improperly heating formula for baby birds), crop lacerations (from incorrectly feeding baby birds or from other trauma), and the entrapment of foreign objects.
What are some of the signs of crop infection?
As a rule, most birds with crop infections regurgitate. The material regurgitated can be food, thick, mucoid crop fluid, or both. While other conditions can certainly cause regurgitation in birds, the frequency of crop infection dictates diagnostic efforts being directed toward crop problems before other more serious conditions are investigated.
How are crop infections diagnosed?
Usually, a procedure called a crop wash or crop aspirate is performed. The veterinarian places a small amount of water into the crop using a feeding tube. Some of the fluid is then removed and tested for infectious organisms. The testing may include direct microscopic examination often using special stains, or performing cultures of the crop fluid.
If an answer is not determined from these tests, other tests, including swabbing the crop directly, radiographs (X-rays), or a crop biopsy, may be needed. Tests that give basic information about the overall health of the bird such as blood profiles may also be recommended.
How are crop infections treated?
Once the correct diagnosis is made, your veterinarian will determine the best course of treatment. Bacterial infections are treated with antibiotics. Yeast infections are most commonly treated with a drug called nystatin. Impactions of the crop, crop burns, lacerations, and entrapment of foreign objects in the crop may require a combination of medical and surgical therapy. Crop infections can be very serious and may require your bird be hospitalized and treated.