Classification: Protist - group Ciliata (ciliated protozoa)
Cell characteristics: Trophozoites - oval in shape, 50 to 100 micrometers long by 40 to 70 micrometers wide, similar to a paramecium. Cilia cover the cell surface. Internal macronucleus is prominent, micronucleus not prominent; sometimes anterior cytosome is visible. Cysts - usually spherical, diameter from 50 to 75 micrometers. Cyst wall visible with no cilia. Prominent macronucleus, non-prominent micronucleus.
Source: Pigs, sheep, cattle
Pathogenicity: Causative agent of balantidiasis. This disease is marked by nausea, vomiting, diarrhea and intestinal colic. Healthy hosts are usually resistant to infection. Cyst is the infectious stage.
Balantidium coli
