I am sure my studio smells like a million dogs to them(and to other dogs) There are a few cats that do well, but, it is the minority. I know what I do well, and I accept what is not my strong points.
I think its a lot about being able to get into your subject's head. No matter who/what they are. Kids/dogs, are my easiest subjects to do that with. Hence, why I market to them.
I have not had cats, so, I just cannot get into their heads and know how they think. I can read a dog's or kid's body language and tell you exactly how far we can push and how to get expression from them.