How I Keep My Budgie's Avian Gastric Yeast In Check (The Cure For Avian Gastric Yeast/Megabacteria)
Avian gastric yeast or otherwise known as Macrorhabdus ornithogaster (also referred to as megabacteria) is a significant gastrointestinal health concern that affects birds, particularly pet birds and poultry. This condition, which can lead to severe digestive disturbances and overall decline in avian health, has garnered attention from avian veterinarians and researchers worldwide. In this detailed introduction, we will explore the intricacies of avian gastric yeast shedding light on its symptoms, transmission, diagnosis, and potential treatments.
Fig 26.26 Clinical Avian Medicine Vol II Page 672.
Avian Gastric Yeast (Macrorhabdus ornithogaster)
1.1 Definition and Background: Avian gastric yeast, scientifically referred to as Macrorhabdus ornithogaster, is a fungal infection that targets the gastrointestinal tract of various bird species. While this condition has been observed in both wild and captive birds, it poses a significant concern for pet bird owners and poultry farmers due to its potential for causing severe health issues. Avian gastric yeast has been identified as a type of yeast that predominantly affects the proventriculus, a section of the bird's stomach responsible for initial digestion.
1.2 Symptoms and Clinical Presentation: Infected birds with avian gastric yeast may exhibit a range of clinical signs, which can vary depending on the severity of the infection. Common symptoms include regurgitation, weight loss, decreased appetite, and lethargy. As the infection progresses, birds may develop discomfort, indicated by fluffing of feathers and adopting a hunched posture. In more severe cases, avian gastric yeast can lead to crop stasis, a condition in which food is not adequately emptied from the crop, causing additional complications.
1.3 Transmission and Susceptibility: The precise mode of transmission of avian gastric yeast remains an area of ongoing research. However, it is suspected that the infection spreads through contaminated food and water sources. Additionally, direct contact with infected birds may play a role in the transmission process. The susceptibility of various bird species to avian gastric yeast can differ, with some species being more vulnerable to infection than others.
1.4 Diagnosis and Veterinary Examination: Diagnosing avian gastric yeast requires a thorough veterinary examination. Avian veterinarians may employ a combination of physical examinations, fecal testing, crop washes, and endoscopy to identify the presence of Macrorhabdus ornithogaster. Crop washes, in particular, involve flushing the crop with a sterile solution to collect samples for analysis. The definitive diagnosis is crucial for initiating appropriate and timely treatment.
1.5 Treatment and Management: The treatment of avian gastric yeast typically involves the administration of antifungal medications prescribed by avian veterinarians (in this case Amphotericin B). These medications are aimed at combating yeast infection in the bird's gastrointestinal tract. Additionally, supportive care, such as providing a nutritious diet, eliminating any sugar intake, and minimizing stress, is essential to aid in the bird's recovery and bolster its immune system. Unfortunately, there is no specific treatment for megabacteria that has consistently demonstrated high efficacy.
Some common symptoms of AGY in budgerigars include:
Weight Loss: Infected budgerigars may exhibit gradual or sudden weight loss. This can be noticeable as a decrease in body condition or a "skinny" appearance.
Regurgitation: Birds with AGY may regurgitate or vomit, sometimes containing undigested food or an abnormal appearance.
Swollen Crop: The crop, the pouch-like structure in the bird's throat where food is temporarily stored, may appear swollen or distended due to AGY infection.
Diarrhea: Affected budgerigars may have loose or watery droppings.
Increased Drinking: Budgies with AGY might drink more water than usual due to the impact of the infection on their digestive system.
Decreased Activity and Energy: Infected birds may become lethargic, less active, and show a reduced interest in their usual activities.
Fluffed Feathers: The bird's feathers may appear fluffed up, indicating a possible illness or discomfort.
Poor Appetite: Budgerigars with AGY may show a decreased appetite and may be reluctant to eat.
Distended Abdomen: In severe cases, the abdomen may appear swollen due to the infection and its impact on the digestive system.
In 2021 December, I adopted a little blue bird whom I had named Hatchin. The lady I adopted him from kept multiple budgies, the condition in which they were kept in was less than ideal. The large cage was quite unhygienic and unsanitary. His parents originate from rescue centers so I knew that there was a possibility that Hatchin might have a disease. After I got to know him better I realized that something wasn't okay with him, he kept closing his eyes for a few seconds and I could see it on him that he was in discomfort. An inexperienced bird parent would never have noticed that sign. This is why I recommend taking a newly adopted bird to the avian vet for a check-up as soon as possible so that it wouldn't infect your other birds and you find out if it has any disease in a timely manner. The only symptom I can list is that I could see it in his eyes. I had a hunch that something was wrong with him. He ate regularly, he chirped, his poop was normal, and was quite active but my intuition told me that something was ''off''. I took him to the avian vet and as I sat there in the waiting room I begged the angels that the diagnosis wouldn't turn out to be avian gastric yeast (megabacteria). He weighed 30 grams.
The diagnosis was megabacteria. Back then, my mind had associated megabacteria with a death sentence. He also tested positive for e.Coli.
In the course of a few months, he received the following treatment:
Doxycycline injections (antibiotics for e.Coli, 7 doses)
Amphotericin B (antifungal for AGY, on an empty crop, given for 28 days, 2 times a day, one drop into the beak, I repeated the treatment around 3 times)
Probiotics (to make sure the beneficial bacteria in his intestines would grow back since antibiotics destroy beneficial bacteria in the gut)
Apple cider vinegar (which acidifies his intestines, fungi can't thrive in an acidic environment)
Thyme (diluted tea or fresh herb, antifungal properties)
The following test has been performed:
Gram stain (crop and fecal)
Antibiotic resistance test
I repeated this treatment regime a couple of times. One must be careful when administering antibiotics and antifungals. Pathogens become resistant to drugs, including antibiotics and antivirals, primarily due to the process of natural selection and the excessive or inappropriate use of these drugs. When exposed to drugs, pathogens with pre-existing genetic mutations that grant them resistance have a survival advantage, as they can withstand the drug's effects and continue to reproduce. These drug-resistant strains then become dominant in the population. Additionally, horizontal gene transfer between bacteria allows the rapid spread of resistance genes. Furthermore, the overuse and misuse of drugs, such as patients not completing their prescribed antibiotic courses or the widespread use of antibiotics in agriculture and livestock, create selective pressure, promoting the survival and proliferation of drug-resistant pathogens. Consequently, as time progresses, pathogens evolve and adapt to overcome the drugs meant to eradicate them, posing a significant challenge to global health by limiting treatment options and leading to the emergence of difficult-to-treat infections. E. Coli was eradicated by the antibiotic shots, but AGY still remained a problem because he kept coming down with illness every three months. Amphotericin B did not eradicate megabacteria entirely, it only ameliorated the symptoms for a while (3 months).
Current Avian Gastric Yeast Treatment Protocols Are Ineffective
Attempts at treating birds affected by AGY have met with limited success. Traditional antibacterial drugs have no effect on AGY. Amphotericin B, a polyene macrolide antifungal drug, when administered orally (100 mg/kg twice daily) was found to be effective at ameliorating fecal shedding of AGY organisms in affected budgerigars. It is considered the standard for treating birds diagnosed with avian gastric mycosis. I accentuate the word 'ameliorate'.
However, in a follow-up study, several treated birds were observed to return to fecal shedding, suggesting either that reinfection occurred or that therapy was incomplete. Treatment with amphotericin B is also complicated by the need for long-term administration, the cost of the drug and the difficulty of obtaining an oral formulation. Resistance of AGY to amphotericin B has been reported in a flock of budgerigars in Australia.
Oral nystatin and oral lactobacillus are treatments reportedly showing some degree of success; other studies, however, have found these therapies ineffective.
Megabacteria Might Or Might Not Be A Normal Part Of The Avian Microbiome
Birds harbor complex gut bacterial communities that may sustain their ecologies and facilitate their biological roles, distribution, and diversity. Research on gut microbiomes in wild birds is surging and it is clear that they are diverse and important – but strongly influenced by a series of environmental factors.