I really didn't have the best setup for that shot. That was taken with my 18-200mm @ 200mm. If I had planned the shot I would have opened it up to at least f/8 or probably f/5.6. The next day, I came back with my 70-300 which worked much better. While you couldn't see the sun (near sunset), it was taken in the direction of where the sun was setting.
You have less problem when you exhibit fearlessness, or even just calmness. I have stared down dogs that were coming at me. I have lots of experience. Just don't try it going against two or more dogs.