Pulling out doll's hair

My son has a lovey/doll that he's been attached to his whole life. He's 23 months. Recently, he's begun biting/pulling out the doll's hair with his teeth. If I discourage it, he does it more. At best, I'm hoping it's teething 2 yr old molars. At worst, I'm scared it's a sign of anxiety. What do you think? (This poor doll is half bald now).