At such a close range as that, the "shallow depth of field look" will actually look pretty great at f/8 to f/11! The trick is getting the eyes in focus, and also a good portion of the muzzle. The common mistake is to focus right ON the nose, the black nose part, but that wastes a small part of the DOF band that is in front of the focus point. The issue is, really, that at very close distances, which this shot is made at, there is simply not much depth of field, even when stopped down to f/8. At THIS close a distance, my ideal working f/stop in bright light is actually going to be f/16. ANd no, I am not kidding you. Forget diffraction worries--that's theoretical nonsense...the #1 priority is enough DOF to get a pleasing dog portrait. The longer the breed's snout, the more you need; on a pug, you could be at f/5.6...on a weiner dog, with that loooong snout, f/5.6 will not have the DOF needed.