Giardia infection in budgerigars.
Budgerigars (Melopsittacus undulatus) from two different breeding colonies were found to have Giardia infection. Light microscopy, scanning electron microscopy and in vitro and in vivo studies confirmed the species was G. psittaci. Chicks were clinically affected and showed signs of retarded growth, dehydration and diarrhoea. The faeces of adult birds treated with metronidazole in drinking water were negative for Giardia 5 days after treatment. Megabacteria were also found in adult birds but were not treated. This study extends the known host range for Giardia in Australia to include budgerigars.