What happens if my rabbit's head tilt isn't treated by a veterinarian?

Head tilts in rabbits are usually due to one of two things, an ear infection or a neurologic condition caused by a parasite. Both of these conditions will require treatment by a veterinarian in order to get better. The head tilt will likely get worse and worse if the underlying cause goes untreated. If the cause is the parasite (E. Cuniculi), it will eventually spread to other organ systems and cause death. Even if it is just an ear infection, these can be painful and irritating enough to a rabbit to make them not want to eat. A rabbit who isn't eating is often one that develops gastric stasis, which is another deadly condition. Overall, I would recommend getting Buzz seen by a vet sometime sooner than later.