Histopathology of the intestine of a dog with salmon poisoning disease. A Neorickettsia-infected adult stage trematode (note its sucker) is tightly attached to the intestinal epithelium and caused deep indentation at the contact site. Extensive inflammation is present in the lamina propria and submucosa around the attachment site. Paraffin-embedded section, H & E staining.
Courtesy of Dr. Yasuko Rikihisa.