Symptoms:
Frayed, decaying, damaged fins and in very severe cases just a stump is left remaining. Fins may be red at the base, with skin ulcers. The fish would most likely be in poor health so clouded eyes and lethargy are also common.
Cure:
First and foremost correct poor water conditions, check pH and correct as required. Antibiotics from your vet will treat the infection, however permanent scarring may occur if the rot is extensive. Fin Rot medication is also available from pet shops. Death can occur if left untreated, or left too late.
Remember, water quality is always extremely important- so always check that first as it is often the cause of disease in aquarium fish. When treating sick fish, try to put the least amount of stress on them as possible, as stress will hinder the heeling process. Another thing is to remember is that generally, a happy fish is a healthy fish.