Just because you mention dogs- I have enormous giant breed dogs and have had great success using small cages that force the dogs to step around smaller plants. At one point I had over 200 of these in the fenced portion of my yard where the dogs have free reign and I never lost a plant. Once the plants are well established and of enough size I just remove (and reuse) the cage.

Hydrangeas are woody plants(shrubs) and don't lend themselves to division, like one would normally do with perennials. Having said that, they are also caning shrubs, meaning they produce new stem growth from the base (i.e., no "trunks") so technically could be split into one or more plants. I'd hesitate to do so intentionally as you run the risk of killing the entire plant if not handled correctly. But sometimes when digging for transplanting, it happens on its own. And that usually turns out just fine :-)

To succeed with a plant division you need both roots and crown with,usually some stem growth. As gardengal48 mentioned, such is not usually possible with a plant that grows from a single stem or trunk. Sometimes you may have a plant that has stem growth at ground level that has grown roots where it touched the ground. This can usually be separated from the parent plant, and grown as a new plant. Al

I know I can't split the limelight... nothing to split. The picture I posted above is, what I thought at least, was the annabelle. Maybe its not but it seems I can't split the annabelle.

Thanks for all the advise everyone!

I have pulled several rooted Annabelle shoots from the mother plant and replanted successfully. It looks like you have quite a few good candidates in your photo. Try to get one that is far from the center as it should have more extensive roots.
It is still early enough in the season to move the limelight. Just make sure you water the transplanted or potted hydrangea often.
Best of Luck!

Thanks, jemboysch! I will probably try to move the limelight this coming weekend to a new pot until I can figure out where its final home will be in the yard :)