Stepping out of your photographic comfort zone is quite good to do every now and then. Although dog photography is what I mainly do with the camera, taking pictures of retrievers (even flatcoats) is quite different to taking pictures of sighthounds at full speed.
The speed of the dogs is also a real test of your equipment. It’s the first time that our 30D’s focus points were not enough ;). But I did end up with several good shots, so prepare for more dogs.