Both are great pics, Mark. The second one seems to put more emphasis on the dog while the first gives an equal billing to both the dog and girl. If I had to pick one for a calendar focusing on dogs, Id go with the second.
I echo Mark's sentiments; the dog in the second is in sharper focus and the focus is on him. Both are lovely, and you've done such a fine job with the lights and post processing. Her skin looks flawless.
I love the pics of this lovely dog. I also always love seeing the interaction between a dog and a human. I like the clean background and the lighting. Do you have to make a choice or can you submit both? However, if only one can be submitted, I would go with #2 because, as mentioned above, it places more emphasis on the beautiful Labrador, Mac...
BTW: in the yearly competition for the www.doodlekisses.com calendar, the organization wants only dogs in the images; no humans I wonder if the Lab calendar people have the same rules?
One other thing Mark, Mac in the 2nd image... his teeth are very clean from what I usually see in labs. Were the teeth cleaned for (or PP in) this picture or is Mac just a model of oral hygiene?