Animal Parts — David E. Knop

Cochiti Pueblo Policeman Peter Romero, a mean dog best caged, is stunned when he discovers a mountain lion he has killed sitting on his bed at home. The big cat demands vengeance for his mate and cubs killed by poachers. Game wardens die while Romero pursues a rocky, twisting trail from the rugged slopes of New Mexico's Sangre de Cristo Range to the hot, flat prairies of central Oklahoma. He uncovers the killers: a Cheyenne family suffering from the dreaded Windigo Psychosis, a malady that transforms its victims into ravenous monsters who eat everyone they encounter.
Romero attacks the windigos, but is astonished when they will not die. With dog jaws of a windigo crushing his neck, Romero uses his connections to the spirit world to consult a long-dead hunter of the monsters who says the only solution is to change the course of history. He may be too late.