Your qualifier makes it difficult to reply. No one only studies aikido. We all have used tools, played sports, and used our bodies in various ways. Even O'Sensei and the other senior Aikidoka have some experience with other arts, other activities.
That being said, if you're going to ask the question at all, I know many Aikidoka in our organization that use atemi effectively. Some of them have not formally studied any other arts.
I really, really like the flawed cat. I think you could teach him to bark. http://youtu.be/aP3gzee1cps