We proclaim human intelligence to be morally valuable per se because we are human. If we were birds, we would proclaim the ability to fly as morally valuable per se. If we were fish, we would proclaim the ability to live underwater as morally valuable per se. But apart from our obviously self-interested proclamations, there is nothing morally valuable per se about human intelligence.
Being vegan is not a matter of "lifestyle." It is a matter of fundamental moral obligation. Is being vegan a matter of "choice"? Only insofar as we are able to choose to ignore our moral obligations not to exploit the vulnerable.
I certainly believe that we have a moral obligation to care for the dogs, cats, and other nonhumans whose existence we have caused or facilitated as part of the institution of 'pet' ownership. But I maintain that we ought to abolish the institution and stop causing or facilitating the existence of more 'companion' animals.
Veganism is the application of the principle of abolition in your own life; it represents your recognition that animals are not things. Veganism is the recognition of the moral personhood of nonhuman animals.