There was a recent article in the Chicago Tribune about bringing dogs to work with the following quote:

"What we're trying to create here, it's lofty, open, we bring in lunch, we hire younger people. Part of creating the vibe is not just the space but the amenities. Bring in your dog."

http://www.chicagotribune.com/lifestyles/pets/ct-pets-office...

No idea if that counts as ageism. Is it any worse than mentioning "recent graduate" or "0 - 2 years experience" in your job advertisement?