I had a German Shepard, (best friend I ever had... her name was Bonanza) that made friends with a Coyote.
I had Fish & Game experts tell me that was impossible, that I was lying or mistaken. But I wasn't. For a couple of summers the coyote would show up in our front yard, (I was in High School), and play with Bonanza. My Dad and I used to watch them from our living room window frolicking in our front yard.
The coyote didn't visit every night, maybe 2 or 3 times per week. Mostly in the summer but occasionally the coyote would show up in wintertime. Can't really remember for sure but I think they were 'buds' for a couple of summers for sure and maybe more?
I also raised a coyote pup which I eventually let loose. They never do really tame down although with me he was a 'buddy'. When I first turned him free he would come back often to play with me in the front yard (I live/lived in the country). His visits grew fewer and fewer over a few years.... I think maybe 4 years?.... eventually he stopped showing up. - JamesJM