What are Tuberculosis?
Avian tuberculosis (mycobacteriosis) is found worldwide and can infect pet, wild, and domestic birds. It has a long incubation period; clinical signs may not show for weeks or months after being exposed to the disease.
Adults that have compromised immune systems as well as young children are susceptible to contracting avian tuberculosis (Mycobacteriosis). Individuals that were diagnosed with tuberculosis can transmit the disease to birds.
Avian tuberculous (mycobacteriosis) in birds is a highly contagious disease caused by the mycobacteria M. avium and M. genavense. The disease causes tubercles (nodules) and granulomas on the liver and gastrointestinal tract; other organs may also be affected. Additionally, avian tuberculosis (mycobacteriosis) can cause the gross enlargement of organs.
Symptoms of Tuberculosis in Birds
The symptoms of this disease may be different in various avian species. The symptoms of avian tuberculosis (mycobacteriosis) in birds may include:
- Weight loss
- Decreased egg production
- White diarrhea
- Increased thirst
- Dull and/or ruffled feathers
- Swollen abdomen
- Skin ulcers
- Atrophy of the breast muscle
- Hepatic rupture and hemorrhage due to an enlarged liver
- Sudden death
Causes of Tuberculosis in Birds
Avian tuberculosis (mycobacteriosis) is usually caused by mycobacteria M. avium and M. genavense. These two mycobacteria are transmitted by:
- Ingestion of contaminated water or food
- Inhalation of the organism
- The equipment and/or litter are contaminated by the feces of an infected bird.
- Rodents can act as mechanical carriers of the disease.
- The bird is bitten by a tick or mite that carries the organism.
- Humans may transmit the organism on their shoes, clothing and hands.
- Stress factors can enhance the development of the disease (over-crowding, confinement, and malnourishment)
Diagnosis of Tuberculosis in Birds
The veterinarian may want to go over the bird’s medical history. During the consultation please let the veterinarian know what symptoms you have observed and when did they start. He may want to know where the bird is housed and if he shares his cage or pen with other birds.
The veterinarian will then perform a physical exam, which may include listening to the patient’s lungs and heart. He may also palpate the bird’s abdomen and breast muscle. The veterinarian may recommend running a few diagnostic tests. A complete blood count (CBC) will be helpful in determining the patient’s red and white cell and platelets count. Patients with avian tuberculosis (mycobacteriosis) usually have elevated white blood cells and low red blood count. Whole body x-rays and an ultrasound can help identify tubercles, granulomas and/or the enlargement of organs. The veterinarian may also want to culture a feces sample.
A laparoscopy examination may be suggested. This surgical procedure makes a small incision and inserts a fiber-optic instrument through the bird’s abdominal cavity to visualize the organs. The veterinarian is able to see if there are any mycobacterial lesions, enlarged organs or masses. He will also be able to perform a biopsy of the affected organs. Your bird will have to undergo general anesthesia.
Other tests that may help in the diagnosis of avian tuberculosis (mycobacteriosis) include a DNA probe analysis of feces, Haemagglutination test, an enzyme-linked immunosorbent assay (ELISA) and the polymerase chain test (PCR). A tuberculosis test is usually not recommended because it is only 80% accurate.
Treatment of Tuberculosis in Birds
Birds diagnosed with avian tuberculosis (mycobacteriosis) must be placed in quarantine for 12 months. Good sanitation and hygiene must be maintained. The person who is the bird’s care giver should wear gloves and mask while cleaning the cage or pen. Avian tuberculosis (mycobacteriosis) can be treated with several antimicrobial drugs taken orally. Goldenseal is a perennial herb that may be recommended in addition to the antimicrobial medications. Goldenseal has antibiotic properties, which may be beneficial to the patient.
The disease is resistant to many medications. The treatment of this disease will take months and in some cases over a year. It is important to be totally committed and follow the veterinarian treatment plan. If the bird does not respond to the medications the veterinarian may suggest euthanasia.
Recovery of Tuberculosis in Birds
The recovery of avian tuberculosis (mycobacteriosis) has a guarded prognosis. Follow up visits will be required to monitor the bird’s progress, test for the disease, and to make sure the prescribe medications are working. Sometimes the antimicrobial drugs will need to be changed or additional drugs may need to be added to the therapy regimen. Owners of a pet bird with avian tuberculosis (mycobacteriosis) should be seen by a physician and screened for the disease.