She's thrown up several hairballs in the past three days and she's thrown up twice just shortly after eating her food. I haven't switched cat foods but I'm wondering if it's the cat treats my husband bought a few weeks ago because I have been giving both cats treats most everyday the past few days. They are Feline greenies smart bites hairball control. I swear every time I feed or give them something with hairball control they start hacking them (hairballs) up like crazy! I'm going to stop giving the treats and see what happens.