Buck Rogers in the 25th Century (1979) : 2x9

Buck and Twiki come across the survivors of a failed colony, a young widow and her son. The woman tells Buck that the other colonists all fled the planet as the result of a plague. Buck is confused by the woman's refusal to leave the planet despite being repeatedly being menaced by a goat-man named Pangor; but he soon discovers the truth about the plague when he contracts it and begins to turn into a goat-man himself.