The problem with using cats is they take too much kindling to get them going, and since the fur is a big part of the BTUs, the short hair varieties are almost worthless for fuel. Worse than poplar, really. Harder to light, too.
Siamese are probably the worst, in my experience.
At least the long-hairs flame up pretty good. Now, if you can get a good supply of Burmese, that's not bad. Not quite as good as oak, but still, for a cat, it's pretty good.