Symptoms: The bird will have a wet vent and diarrhea. It will be fluffed up and although has some energy when approached will sleep a lot.
Cause: Coccidiosis is a parasite that is found in the intestinal lining of birds. It is easily transmitted to other birds through interaction. Unless treated correctly you will start to notice more and more of your birds developing the same symptoms.
Treatment: After exact diagnosis of coccidiosis a correct course of Sulphadim / Sulfonamide is required. Sulfonamide antibiotic for the treatment of Coccidiosis, Enteritis, susceptible bacterial infections, and diarrhea in ornamental caged birds. When administering ensure the cage is cleaned daily to prevent re-infestation. This broad spectrum antibiotic is normally administered through the drinking water. Use only with glass or plastic drinking containers.
Pet Bird Care Us magazine, Common Finch Diseases: Aries Munandi, June 2015