I would agree with skieur - I spent some time trying to get similar shots of our black cat and its not easy. Flash set for fill flash (typically negative exposure compensation so that its just filling in light and not dominating the scene) and then I exposed for the brighter background behind the cat - relying on flash to help with the cat. I experimented around that and have yet to really study the results (ie what flash compensation - if any - worked best in the scene).
And yes a good low angle can really work well