Mange was a type of skin disease caused by parasitic mites.
In November 2154, Hoshi Sato described Porthos to Jonathan Archer as mangy as part of a hostile discourse in preparation for the arrival of a Tellarite delegation. (ENT: "Babel One")
In 2375, General Martok reminisced with Benjamin Sisko about a pet targ he once owned, which he described as a "filthy, mangy beast." (DS9: "Strange Bedfellows")