Proventricular dilatation disease, also known as macaw wasting disease, is caused by infectious parrot bornavirus. It is a fatal neurologic and gastrointestinal ailment found in more than 80 percent of parrot species. Large parrots can be severely affected by this wasting-like disease that causes paralysis and partial blockage of the digestive tract. Traditional diagnostic tests include imaging studies and identification of the virus in blood or feces.
PDD is very challenging to diagnose in its early stages. While several diagnostic tools are available through commercial and university laboratories, test results vary widely and the accuracy of each test remains controversial. Morris Animal Foundation-funded researchers from Texas A&M evaluated the advantages and limitations of four available PDD tests – reverse transcriptase PCR test on feces, ELISA test on serum, immunofluorescent assay on serum, and Western blot on serum. Their objective was to find the most accurate PDD diagnostic strategy. Dr. Ian Tizard, BMVS, PhD, Texas A&M Agrilife Research, was the principal investigator on the study.
After analysis of each test alone and in combination, researchers highly recommend that veterinarians use the PCR test in combination with either immunoflueorescence or Western blot assays for optimal diagnostic results. This method detected PDD infection in the majority of parrots tested and was superior over other currently available testing strategies.
Early and effective diagnosis of PDD is crucial in preventing transmission of infections to other birds and allows earlier intervention before the onset of severe disease. Continued PDD research by the Texas A&M team includes ongoing improvement of diagnostic testing strategies and accuracy as well as working on preventive measures, such as a vaccine against PDD. Findings from this study were presented at the annual meeting of the American Association of Avian Veterinarians.