There was something in the yard last night

Based on the prints left in the frost it has doggy like paws about half the size of Apollo’s.  I’m thinking coyote, but it could be stray dog.  Whatever it was Apollo was NOT AMUSED.  He spent half an hour this morning dragging me around the front yard, sniffing prints, peeing on strategic spots, and huffing away to himself.  He’s now sitting infront of one of the front windows and won’t even come to breakfast.