Avian Gastric Yeast (Mycobacteriosis) What is it ?

Aviculturist are aware of the dreaded disease PBFD, and the headache to the best of Veterinarian Feather Plucking followed by the PDD. But this disease Avian Gastric Yeast /Mycobacteriosis has gone unnoticed. It is a silent killer. It is passed off on many occasions as Going light / Sukka. Going light is just a symptom of many diseases and an indication that the bird is sick.

Mycobacterium, belongs to genes Mycobacteriaceae, This bacteria’s are very common in all animals, birds and humans. Mycobacteriosis, is also known as Avian Tuberculosis it is caused by bacteria called Mycobacterium bovis, M. avium and M. tuberculosis, It is a zoonotic disease, that is communicable between humans and animals.

Mycobacterium avium is a common and serious pathogen in poultry and is also found in pet birds.Mycobacteriosis or Avian tuberculosis (TB) is mainly caused by M. avium, and in rare cases by M. intracellulare and M. genovense. Very young or elderly people with weak immune system can be infected by this disease if in contact with the bird.

M.avium is an organism found in soil and water and is the most common cause of TB in birds, That can survive for long time in the environment and in carrier birds. Transmission of this Bacteria occur through ingestion or inhalation of dust from feathers and dried fecal matter.

It was earlier recognised as a bacterium, But recent studies suggest that this organism are actually yeast. A fungi, that mimic bacteria. The new studies support the theory as a fungi as fungal medications work more effectively than antibiotics in treatment this disease - Megabacteriosis / Avian Gastric Yeast. Due to the its fungal nature, it is now referred to as Avian Gastric Yeast (AGY).

Three types of disease occur in birds due to AGY / Megabacteriosis :

1. Classic Form
2. Para-Tuberculous Form
3. Non-Tuberculous

Three types of disease occur in birds:

1. Classic Form : Rarely seen as a pox lesion on the skin surface but the tubercules or granulomas form is seen in the organs – liver, lungs, spleen, intestines.The most common symptoms seen is muscle wasting, emaciation, weakness, lethargy, lameness and diarrhoea.
2. Paratuberculous Form : Has been found to infect Amazon parrots and Pionus It is found as lesions in the intestinal tract. It is sometimes mistaken PDD as it shows the same symptoms.
3. Non-tuberculous Form : Is very difficult to detect and goes unrecognized like in parakeets, Canaries and finches.

Mycobacteriosis or Avian Tuberculosis is at times difficult to diagnose in birds due to lack of symptoms and frequent fecal shedding. A definite diagnosis is only possible through Necropsy or through feces examination.

Symptoms of AGY / Megabacteriosis in Birds :

1. Your bird may have pale and cold feet.
2. Affected bird show signs of good appetite, but actually they just peck or hull the seeds.
3. Regurgitation (Vomiting) is the most common symptom of this disease.
4. Chronic weight loss - Affected birds die after long term weight loss.
5. When the disease reaches the final stage the birds look fluffed, stressed and lethargic.
6. Undigested seeds or pellets (bird feed) in the droppings.
7. Bulky dark feces.
8. Diarrhea

Birds infected with Mycobacteriosis should be kept separately and quarantined. Humans can also get infected through contact with the infected birds. The protocol of Quarantine for infected birds and those birds in contact with the infected birds is 24 months and to be tested every 6 – 12 weeks for update on the status. disease at six-to-twelve week intervals.

Treatment of Mycobacteriumis is very long, and usually not successful Some Aviculturist euthanize such birds. The best method to prevent this disease from entering the Aviary is strict quarantine procedure. As birds can be carriers of this disease without any symptoms.. It is very important that all the new birds be tested for Mycobacteriosis.

All Mycobacteriosis isolates tested have been found to be resistant to all the currently used human anti tuberculous drugs. Hence treatment is very difficult and is not considered as an effective option.

Going light /Sukka is just a symptom of a underlying disease. But the interesting point to note is that birds suffering from from Going light / Sukka become weak, become inactive and have loss of appetite and if not treated on time die in a short period of time.

But in case of birds suffering from Mycobacteriosis in spite of going light / Sukka. (Where the keel bone becomes as sharp as knife. The bird continues to be active, with a good appetite sometimes eating more than the healthy bird. But not putting on weight. But continues to survive in this condition for years.

Hygiene and disinfection of the Aviary or the bird room is very important. Keep Rodents, Lizards and wild Birds from coming into direct contact with the birds. avoid fruits as much as possible as sugar helps the growth of yeast.

One medication that has proved to be effective is Amphotericin B. Which is available in Australia under several brand names. Fluconazole has been found to be effective in treating AGY. The other options are to treat the bird with Citric acid, 0.80 mg / 1 litres of water or Apple cider vinegar 10 ml / litre of water. Probiotics should be provided as they help in lowering the digestive tract pH by producing lactic acid. The birds should also be treated for secondary infection with Enrofloxacin.

Article Source : Sadiq Bhaimia Sir