From Dog

Secnidazole is a derivative of metronidazole.

Trichomonads such as Giardia spp and Cryptosporidium spp lack the mitochondria needed for aerobic metabolism. Instead, pyruvate is generated by glycolysis and fermented in reductive organelles called hydrogenosomes. This reductive metabolic pathway serves as the basis for the susceptibility of trichomonads to 5-nitroimidazole antibiotics, such as ronidazole.