Thanks so much for the input folks.
I am looking at my current equipment, a Sigma SD14 and lenses, flashes etc and I am coming to the realization that they won't work for pet photography. While it is absolutely wonderful for photographing flora etc the buffer would just choke on trying to take pictures of a dog running around etc...
So now I am looking at getting a another system strictly for this purpose. So far the Nikon D300/24-70/70-200 or Sony a700/24-70/70-200 have made the short list. I don't want to turn this into a 'brand battle' so please don't take it as that...
Julie - I notice that you shoot with an Olympus system. Are you using an E3? If so, how do you find the focus speed and overall camera speed? (I had an E1 and loved it...)
Thanks again to everyone for your help.