The first time I posted cat photos here, I was sort of apologetic about it, as if it detracted from the otherwise serious and important subject matter (city parks, flowers, statues, travel photos, etc.). That was before I realized that other people have parlayed owning a cat and a camera into vast internet media empires, untold fame and riches, and so forth. And serious or not, I suspect cat photos are of far more universal interest than semi-abstract pics of yet another 70's sculpture on the Transit Mall would be, for example.
So right now the one area that may need some attention is the lens department. We don't get a lot of ambient light here on gloomy fall/winter/spring days like today, and getting non-blurry photos of a kitten with lightning reflexes means either A.) underexposing & trying to fix it later, or B.) redlining the ISO setting and accepting an ugly amount of sensor noise, or C.) both, which is pretty much what you're looking at here.
And then there's option D, which involves getting a faster pro-grade zoom lens. One site I looked at suggested using a 70-200mm lens, preferably f/2.8. I don't have one of those, but it seems that Canon makes several lenses matching those specs, such as the 70-200 f/2.8L IS USM , for instance. I do realize it's a big, heavy, $1900 lens. But if, hypothetically, I had a vast cat-based interweb media empire, the lens would count as a business expense. As, I suppose, would cat food and vet bills. So there's that. Plus I'm fairly sure there would be an incremental improvement in photo quality, and I'd prefer to think that's not just gear lust talking. So there's that, too.
The cat, you understand, has not yet been consulted on any of this media empire nonsense.