In order to be a successful rabbit farmer, it is important to distinguish between a normal and sick rabbit. Sick rabbits show special signs.
Not eating; if your rabbit has not eaten feed in the last 8 to 10 hours then it is sick. You can try giving it pineapple juice as it helps remove obstruction incase something has blocked its GIT. Weight loss is another sign of sickness hence if your bunnies are loosing weight faster or the bones are showing too much. Other reasons that can cause loss of weight is when the bunnies are infested with worms and when they are aged ie greater than 7 months.
Disease signs
Hunched positions. If your rabbit is lying in hunched positions, try giving them critical care and if this fails to work then consider taking them to a vet.
Shading patches of fur. If a rabbit has patches that have no fur and you can see the skin directly then this is a sign that that it has lice and you have to control them.
Grinding of the teeth. This shows that the bunny is in pain.
If they have any wet discharge from the mouth, ears and the nose.
When the rabbit fails to poop. Normally, a rabbit is supposed to poop daily and the poop should be big, brown and not wet. Call a vet if there is hair in the poop.
Acting differently and screaming. Screaming shows that the rabbit is in much pain.