Assalamualaikum wbt
Rabbit can suffer a range of diseases which can be mild to deadly types of diseases. Outdoor rabbits (the one that's kept in the hutch/cage) usually are prone to any disease compare to indoor rabbits. These are some of the common problems that make your rabbit become uncomfortable
1. Diarrhea
There're many reasons for diarrhea, the most common is because of the food. If you feed rabbits with too many greens, they're most probably get a diarrhea. The solution is ensure the bunny stays hydrated as best as possible. Vet is the solution but if you can't make it to the vet, you must feed her with fresh green hay and provide a fresh water all the time. Some inject Gatorade/Pedialite to rabbit's mouth as the electrolytes in both drink can help the rabbit's hydrated.
Imagine you've this on you feet....urghhh
2. Sore hocks
Obesity, long nails and wired cage can cause this sore hocks. It's pain to watch rabbit having this kind of problem. If it's not too serious just make sure that the cage is always dry or provide a piece of drywall as a sitting board in the cage. If it's too serious, treat the wound with some iodine and antibiotic cream.
3. Fur loss and dandruff
It's probably cause by fur mites. The treatment can be vary, the simplest one is by using a Listerine mouthwash. Just soak a cotton ball in the Listerine and dab the infected area every day until the fur has started to grow back. The fastest treatment is by inject the rabbit with some kind of medicine (vet usually know it). But don't simply wash your rabbit with anti dandruff shampoo, it will not solve this problem.
Early treatment can prevent this from occur.
4. Crust in the ears
It's cause by ear mites. If your rabbit is constantly shaking and scratching its ears, then she is probably infected with ear mites. Use a mineral oil or baby oil to the rabbit's ears everyday. But usually one shot of medicine can heal all mites-ear mites, fur mites etc. So the best solution is to bring your rabbit to the vet.
Do you know that rabbit fever can also affecting human? Also known as Tularemia which is caused by the bacterium Francisella tularensis is highly virulent in humans and domestic rabbit. So if you found out that your rabbit got a fever, and then you start to feel that you also got a fever, take a medicine for both before it's too late. You should find this guy to alleviate your pain.