Twitter is appalling, but I finally found an account I like: Can You Pet The Dog?
A catalog of pettable and non-pettable dogs in video games. Manual input resulting in visual representation of petting is required for affirmation.
As noted in the latest tweet, you cannot pet the dog in Shadow of The Collossus. You can pet the horse.
from Boing Boing https://boingboing.net/2019/04/17/games-with-dogs-you-can-pet.html