I've been messing around on google fight this morning. I believe I have the definitive answer as a result:
Cat Vs Dog:
Cat: 376, 000, 000
Dog: 302, 000, 000
As one can see, it is a scientific fact that a cat is better than a dog. The result speaks for itself.
However, one cannot allow a single experiment to cloud judgement. Therefore, a second test is necessary aimed to further prove which is better:
Cats Vs Dogs
Cats: 101, 000, 000
Dogs: 159, 000, 000
This test shows a different result. This can be attributed to the "pack mentality" of dogs being far more palatable to the general public. This conclusively shows that a single cat is better than a single dog, but a pack of dogs will always be victorious over a pack of cats.
To go one step further and give a definitive conclusion, one must add the two figures together. The superior animal will obviously, and from this point in history be scientifically proven to, be the one with the highest figure:
Cats: 477, 000, 000
Dogs: 461, 000, 000
As the above result highlights, cats are clearly "better" than dogs with around 3.3% more of the popular google vote.