Can you describe the noise at all? Is he still eating, drinking, pooping regularly? My bunny sometimes makes little snoring noises almost like squeaks when she’s laying down sleeping but it’s normal for her. Is he showing any other symptoms of feeling sick?

You should ask your vet. When bunnies get airway infections, they can get squeaky breathing, they can also get ear infections from the same bacteria. If your vet listens to his lungs with a stethoscope, they can hear right away if there are abnormal breathing sounds. Then they will most likely prescribe him a week or two of antibiotics.

Do you know if he was around other bunnies while in for surgery? There is a bacteria called E Cuniculli that causes breathing symptoms, snotty nose, runny eyes and audible snuffling when breathing normally. Its normally picked up from other bunnies in enclosed areas like kennels or shelters. Our lionhead bunny eventually passed away from as we had no idea, he had it his entire life and we just thought he was a particularly loud breather. His post mortem showed the bacteria up. We had bonded him with my young dwarf lop who about a year after exposure started to show the same symptoms, I took him to vet and did a course of treatment and he is fine now. Snuffly breathing gone, no more runny nose and eyes, healthy bun. Treatment is called panacur. Might be worth asking vet about this?