Pythium is a genus of parasitic oomycotes. Most species are plant parasites, but Pythium insidiosum is an important pathogen of animals. They were formerly classified as fungi; the feet of the fungus gnat are frequently a vector for their transmission.

Pythium is a genus of parasitic oomycotes. Most species are plant parasites, but Pythium insidiosum is an important pathogen of animals. They were formerly classified as fungi; the feet of the fungus gnat are frequently a vector for their transmission.