Editing Corid:

General treatment for Coccidia, can be used as a preventive for rabbits who have been on the ground, will treat most  cases of coccidia that have been caught early, may not be effective for treating more advanced cases. 
Consider the case more advanced if the rabbit is showing signs such as
  
*Depression
*Anorexia
*Anemia
*Signs of pain such as hunching
*Pale mucous membranes
*Blood or mucous in the feces 
*Poor coat condition
*Dehydration
*Weight loss or poor weight gainor growth
*In severe cases of intestinal coccidiosis intussusception, convulsions or paralysis or fatality may occur
*In severe cases of hepatic coccidiosis weakness, liver damage, and bile duct damage may occur, followed by coma

Toltrazuril (Baycox) should be used in more advanced cases as it will completely eradicate the parasites'.