Tyzzer's disease in a neonatal rainbow lorikeet (Trichoglossus haematodus)

A captive-born 8-day-old male rainbow lorikeet (Trichoglossus haematodus) w as found dead. Histologically, there were necrotizing hepatitis, myocarditi s, and ventriculitis. Silver stain revealed argyrophilic filamentous bacill i within hepatocytes, smooth myofibers of the gizzard, and cardiac myofiber s surrounding foci of necrosis. Immunohistochemistry using anti-Clostridium piliforme RT and MSK strain antisera reacted positively against bacilli wi thin hepatocytes, cardiac myofibers, smooth myofibers of the gizzard, and s plenic and intestinal macrophages. Polymerase chain reaction (PCR) assay of paraffin-embedded liver, heart, gizzard, spleen, and small intestine ampli fied the 196-bp DNA fragment specific to 16S ribosomal RNA of C. piliforme. The results of histopathology, immunohistochemistry, and PCR are consisten t with piliforme infection in this lorikeet.