http://www.azgfd.gov/pdfs/h_f/urban_coyote_faq.pdf
This is good. It is from the Arizona Game and Fish Department. It does describe how to make walls coyote proof.
I am working on getting the factual report of the cat taken off of the lanai in Lynnhaven on Livingston Loop. It may take some time. There was another one in Buttonwood that I seriously doubt someone is making up. Her friend/neighbor did post on here and I believe her.
A mother opossum will protect its young. That is the only critter our dogs have had encounters with here in Lynnhaven. Nothing happened but I had to pick up Sport as he was face-to-face with a mother opossum and barking up a storm. Sport was off leash as he usually stayed in the yard at night. Beau, our newer dog is a real chaser of anything. If he saw a coyote in our yard he would chase it and unfortunately that would not end well for him.
Coyotes like cat sized pets from research I have done. I doubt if a single one would take on a standard poodle, German Shepherd, or some other bigger dog. A group of them might.