What Happens When Your Goldfish Has Fin Rot?

Updated April 17, 2017

Some might think that goldfish have a short lifespan, because they often die and are easily replaced. Goldfish actually have a fairly long lifespan if they are cared for properly. Like any living creature, goldfish are susceptible to disease. The main cause of death for a goldfish is illness that is left untreated due to neglect. Many goldfish owners don't realise their fish is sick until it is near death or have already died. Fin Rot is a common illness in goldfish that is easily treated and is not fatal if caught in time.

What Is Fin Rot?

Fin Rot is a fungus or bacteria that grows on the goldfish's fins. The harmful bacteria is called Pseudomonas Fluorescens. Other bacterias that naturally occur on goldfish are Aeromanas Hydrofilia or Flexibacteria. These are not harmful if the fish's immune system is strong. Goldfish develop Fin Rot due to any of these three bacteria when they are stressed. Poor water quality and stressful living conditions can weaken a fish's immune system and make it susceptible to illness. Fin Rot can also be present at the site of an injury on the fish.

What Does it Look Like?

Early stages of Fin Rot appear differently for fungus or bacteria. Fungus-based Fin Rot gives the fin a white-coloured edge. The entire fin can also appear cloudy. Sometimes blood is seen with the white edges. Bacterial infections are seen as ragged edges along the fin as the fin begins to decompose. Either of these is treatable when caught just as the fin edges begin to show symptoms.

How Do I Treat It?

Contact your local pet store and describe the symptoms to them. There are some treatments, such as potassium permanganate or formalin, that are not advised anymore, as they can cause burning on the fin. For fungal infections, ask your pet store for malachite green. This works by dabbing it directly on the fungus with a Q-tip. For bacterial infections, isolate the sick fish in a tank with .03 per cent aquarium salt solution until the rot has stopped growing. An injection called Baytril will also treat fin rot. The pet shop can give you antibiotics to put in the fish tank, or you can feed the fish antibiotic fish food.

Will the Fish Survive?

Fin Rot is not considered a fatal disease if it is treated within a timely manner. Once the rot moves down the fin, it is more difficult to get rid of. If it reaches the base of the fin, it will enter the body and the fish will most likely die. Fin Rot that has moved down the fin is still treatable, and the fish will even regenerate its dead tissue if the disease is treated with the appropriate methods. If the fish doesn't die from the disease entering the body, the fin will stay damaged and it will be disabled and possibly be attacked or eaten by other fish.

Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

Mary Johnson-Gerard began writing professionally in 1975 and expanded to writing online in 2003. She has been published on the Frenzyness Divorce Blog and on Neumind International Pte Ltd. Her book "When Divorce Hurts Too Long—Ouch" was published in 2009. Johnson-Gerard holds a doctorate in educational psychology from the University of Missouri.