This is obviously difficult to say something definite about, but the squeeky wheezy sounds does remind me of when my bun Bam had a lower airway infection (light case of pneumonia). He could have got it from choking on a pellet -the acute situation was dealt with swiftly when it happened, and the pneumonia only  manifested months later.

A lung infection is of course serious. My bun needed Bactrim for 2 weeks together with bricanyl (pills that I dissolved in water). He made a full recovery even though he was old.

That you hear these “new” sounds when he’s relaxed/resting is a bit worrisome. Do they get worse when he is excited (like for a treat)?

I once had a very vocal bun, he “talked” a lot (different type sounds for different situations). He sometimes snored rather loudly.

Do you think the sounds come from his lungs or from his nose?

Yes, it is hard to say. Typically though, a wheezing sound while breathing is caused by an obstruction in the airway. In rabbits, this tends to be an infection in the upper or lower airway. Dwarf rabbits are more prone to having sinus issues. All of the structures are smooshed, creating places where bacteria and mucus to accumulate, leading to an upper respiratory infection. Or, as Bam explained, some things can cause pneumonia, which is an infection in the lower portion of the respiratory system. These things just happen sometimes, despite owners doing everything right. Unfortunately, these things also do not go away on their own. Antibiotics are needed to clear the infection before it worsens.

The first audio sounds like my vocal bun Vilde. He used to make it while he was happily running across the floor. That sound seemed to come from deep within him, so to speak, not the nose or lungs.

The only things I can think for a vet trip of would be to get him to associate the carrier with nice things, which means food. Since treats shouldnt be given in abundance, maybe you could put some fresh herbs and maybe a few pellets in the carrier and leave it open on the floor so he goes in there and finds nice things in it? You could do this every day whether or not your vet thinks you should come in with him. It never hurts to have a bun that likes his carrier. Saves lots of time and stress in case sth happens.

Rabbits (as a general rule) don’t love transports, so it’d be best if you could sit with him in the backseat (its obviously not very safe to have a carrier in your lap in the front seat). Talk to him during the ride. My vet recommends fresh herbs in the carrier for trips, because there’s something about the fragrance that seems to calm rabbits.

If your vet is sees cats and dogs as well as rabbits, you could perhaps ask if you can wait in the car until it’s your turn -dogs tend to be barky in vet clinic waiting rooms and rabbits really don’t like barking dogs. An early appointment can help too, because then there’s less risk of a dog or cat having been in the exam room just before you.

Bring a towel for the exam table, they are as a rule slippery for reasons of hygiene.

If you get to wait in an exam room, my vet recommends putting the carrier on the floor and opening it, so the bun can explore the room. Not all buns want to explore the room, but the option to can be calming.