Macrorhadbus (Megabacteria)

Still commonly called megabacteria due to its appearance on fecal gram stain as an extremely large, gram, positive rod, this organism is actually a yeast. Macrorhabdosis have been proposed as the definitive name for this disease.

Originally, canaries and budgerigars were recognized as being infected with this organism. Other species that have been commonly documented to be infected include lovebirds, cockatiels, and parrotlets.

Signs of Illness
The most common presentation is a chronic condition, where the birds often appear healthy and look as though they are eating as well or better than normal. They display the “masking” syndrome of appearing to eat, to avoid detection of weakness. Regurgitation is common. You may not see your bird vomit, but the appearance of sticky feathers on top of the head is the usual indication that it has been regurgitating. There may be diarrhea, increased urine, and for those birds that eat seed, you may see them passing undigested seed in the stool. These birds gradually lose weight, and by the time you notice that they are acting ill, they are often extremely emaciated.

There are several indications on blood work that your veterinarian can use to tentatively diagnose this disease. Also, the organism may be seen on a fecal examination, which is a done from the droppings. On larger birds, barium contrast study X-rays may also give an indication of stomach ulceration and other changes in the intestinal tract.

Birds that are affected with other diseases, particularly circovirus, are predisposed to disease from Megabacteria due to their compromised immune system.

Other diseases that may cause these same symptoms include Trichomonas (a protozoan parasite) Candidiasis (another type of milder yeast infection), Proventricular Dilatation Disease (a wasting disease caused by a virus) and toxicity from metals such as lead and zinc.

Treatment of an individual pet bird involves the use of an antifungal mediation. Despite appropriate treatment, affected birds often do not survive a clinical infection. If you have multiple birds housed together or breeding birds, your veterinarian can help you devise a plan to control or eliminate this disease.

Learn more about this disease by contacting our Avian service at your nearest BluePearl veterinary hospital. Here are our hospital locations.

© BluePearl Veterinary Partners 2011