Macrorhabdus ornithogaster, formerly known as “megabacteria,” is a Gram-positive yeast that affects psittacine (most commonly budgerigars) andsome non-psittacine birds.

Clinical Signs

Non-specific (“fluffed” bird), regurgitation, vomiting, loose stools, anorexia, chronic weight loss, emaciation, melena, anemia, sudden death. Birds are often acting hungry and eat readily despite weight loss.

Diagnostics

Fecal cytology to identify the organism
Caution: can be easily washed of slides

PCR >90% sensitivity
+/- Radiographs - to rule in/out other GI diseases
+/- Histopathology if pet passes away and a necropsy is performed

Treatment

Oral treatment is with the medication Amphotericin B or Fluconazole depending on your veterinarian's advice and recommendations.
Apple Cider Vinegar 15 mL/qt of drinking water has also been recommended.

Prognosis

Good with early diagnosis and treatment although some birds can succumb to chronic disease with severe weight loss.

Follow-up

Recheck examination at 14 day mark or sooner if problems, fecal test at end of treatment.