Yesterday I went to Great Falls National Park, on the Virginia side, with my husband and Teddy (our dog). It was a nice day and the park was very busy with people and other dogs. Sadly, we missed many of the fall colors, but it was still a good way to practice taking photos while handling a dog on a leash. Teddy was very good.
I used my standard 18-200 mm lens set at an ISO 200 with an aperture of F8.0 on aperture priority. I found aperture priority worked well while handling a leash with a dog on it. I will however, have to work with Teddy so that he sits and waits while I focus and take the picture.