Dematophytes is a label for a group of three types of fungus that cause skin disease in dogs. The fungus genera are: Microsporum, Epidemophyton, and Trichophyton. There are over forty species belonging to these three genera. These fungus species exist as spores that can survive on and spread through animals, people, soil, and objects. The spores are hardy and can live for years in some conditions. Dematophytes causes fungal infections of a dogs skin, the most notable infections is known as ringworm. Dog health factors may pre dispose them to ringworm, such as poor nutrition, cancer, or a weak immune system.