Chytridiomycosis
Chytridiomycosis is a disease that can kill amphibians, for example frogs.  A fungus causes it.  THe chytrid fungus Batrachochytrium dendrobatidis causes the disease.  The animals can catch it from each other. Chytridiomycosis one reason why there are fewer amphibians on Earth than there were. The fungus has decreased the amphibian population by 30% worldwide.  Many spcies are now extict because they died of chitridiomycosis.  In some species, only a few animals die, but in other species, they all die.  This is called 100% mortality. There is no cure.