Rabbits can get ear mites, ear infections, ectoparasites (fleas, ticks, mites),
and internal parasites, especially if they have been living outside.
Rabbits are especially susceptible to bots. Bots are larvae from flies that become embedded under the skin, after flies lay eggs on the skin. The fly larvae lives this stage of it's life cycle under the skin of the rabbit until it is ready to change (metamorphose) into a fly.