I am having my cats around listening to Dhamma talks and sutta talks; I doubt that they benefit much from that but you never know, some are sitting nicely and quietly on my lap
But seriously, I find it very anthropocentric to assume that only us humans can understand the dhamma because, frankly, we don't really have any idea how animal minds work. I am sure they don't understand our concepts and words but who is to say they do not grasp at least some of the nature of the dhamma as well as we do? Like being in the moment? They accept suffering with an equanamity that humans need to match, first. They are very forgiving, and can be very gentle and kind etc. How do we know that they have their own terms and understanding of the dhamma just because we cannot imagine anything beyond our own words and concepts?
Having said that, the predatory nature of cats is a bit of hindrance for them - though half of my cats would be incapable of killing anything, really (the other half, however, is in fact quite proficient in killing); it's all about socialization.
Btw, my cats are indoor cats with some controlled garden access; and declawing fortunately is considered forbidden in this country as it is considered cruel.