Coyote? Or not.

I saw a fox once. I watched it for about 5 minutes before my companions turned to see what I was looking at. It was obviously a fox even though I had never seen a live one before. It is different with the coyotes. I saw a German Shepherd? once it was moving away from me and two cats and moving downhill. I thought to myself "what was that?" and started following to get a second look. It turned right around and came back towards us while the leashed cat started pulling me away in a frenzy. It still looked like a dog to me, except for the behavior - no backing down whatsoever - police dog? El gato did not stop running until he was inside and upstairs. The second animal I saw was much smaller and trotting on the other pavement very light on its feet. Maybe a dog, maybe not. El gato could not believe that I kept him outside for another 10 minutes - the animal did not challenge us and kept going. When we did eventually go in he didn't calm down for five minutes. But he wasn't so upset that he left me to go upstairs. Then a couple of weeks ago my landlady told me the sad story that someone's cat had been taken by a coyote right out of their yard in front of them. So that made me wonder again what it was that I saw both times.