Thank you for taking in this rabbit in need. To start, I want to highlight that BB forums is not a diagnostic tool and decisions about how to treat your rabbit medically should be made by a rabbit-experienced vet. Hopefully members can give some information based on their experience, but seeing a rabbit vet ASAP when your funds allow is the absolute best course of action at this point.
I think a big determining factor may be age. Do you know if this rabbit is young or old? If he’s young, these conditions may be linked to a weakened, stressed immune system from potentially poor living conditions. This can definitely cause an upper respiratory infection to manifest, where you can see crusty, snot-filled noses as a result. I know Wick had a URI when I first brought him home, and I chalked it up to him being a runt, being generally weaker than he should’ve been. URIs require antibiotics, prescribed by a rabbit vet to treat. If he’s young, it also gives a good chance he can bounce back with the right medical intervention(s).
Rabbits are nose-breathers, so if you find he cannot breath through his nose because there’s snot around it, you can use a clean, warm, damp towel to help break down some snot and dry it with a new, clean towel afterwards. Be gentle, as rabbit noses are sensitive. At major points, I would use a q-tip to get more exact, but not actually enter Wick’s nose (again, nasal cavities are sensitive). Some people have done steam treatments, where they let their rabbit be in a steam bathroom for a few minutes to help get the snot loose. This shouldn’t be done for long periods of time though, because it’s difficult for even humans to breath in a really steamy environment.
The blindness and deaf could be genetic conditions, but also can result from a lot of issues. For example, eye issues can sometimes be linked to dental issues. Overgrown roots can grow into the gum and towards the eyeball, causing pressure and damage. General damage to the eye that was never treated can also become problematic for vision as well. Are you able to look into his ears and ensure they are clean and healthy? Blindness and deafness should definitely be taken to a vet to consider the cause and whether they are “stable” conditions, or a sign of something that may worsen over time.
I will also mention, since you acknowledge funds may be an obstacle, that rabbit medical treatments can be costly. Some vets will agree to payment plans if you inquire about it.
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.