
Well he doesn't necessarily know that hes a wolf/coyote. Only we as readers do. What he knows is that he had fallen in love with coyote boy. Forced to show his love by killing one of the sheeps for coyote boy. And as cowboy dude was going down he assumed that his lover was gonna follow him down shortly. Thats when his boss scolded him because the boss probably knew something he didn't (the fact the boy was a wolf, or there were things like that), so cowboy dude went to look for his lover and found all the sheep gone with blood. And it was more of a gut feeling for him I guess that the boy just used him and wasn't going to go back to him. And out of despair, because he fell in love with coyote boy and had stated previously that he couldn't live without him, he killed himself. Or so we can assume.
Some one explain please what happened?