Bacterial Infections and Diseases that Affect Koi and Goldfish
in the Backyard Ornamental Pond

Bacteria is everywhere.  In the food we eat, in the water we drink and in the pond where our koi and goldfish swim.  There is good bacteria and bad bacteria.  As far as ponds and water gardens go, the good bacteria are nitrifying.  These live in well-aerated, healthy ponds and reside in the biological filter of the pond.  These are the bacteria that are responsible for creating and maintaining the nitrifying cycle of the pond's ecosystem.  We strive to keep good bacteria alive and well. 

It's the bad bacteria that we do not care to have hanging around.  These are bacteria that create disease.  They are borne and raised in mucky, dirty places in the pond like in between the rocks that line the bottom.  Any place that does not get water circulation and does not receive dissolved oxygen will harbor bad bacteria and reproduce it so that it can easily infect our koi and goldfish.

Koi and goldfish, when healthy, have a strong immunity system and are able to withstand a normal amount of bad bacteria (also called "anaerobic" bacteria).  It's when the water quality is bad, the pond is over-stocked or the fish is affected by other stress factors like parasites that koi and goldfish are no longer able to fend off the bad bacteria in their home.  Just like us, if are bodies are run down we cannot throw off colds and sicknesses as easily.   

Bacterial infections and diseases can literally wipe out the majority of your koi and goldfish if they ever get a foot-hold on them.  Sometimes the diseases are secondary to a primary affliction, such as parasites and if we get rid of the aggravating condition the bacterial infection can then heal.  We must, however, treat the bacterial infections as symptoms just as you would a cut, cold or flu.

The Most Common Types of Bacterial Infections in Koi and Goldfish

There are many forms of infection that can manifest inside and outside the fish.  Among the internal infections are Dropsy, Bacterial Gill Disease and Septicemia.  Much more common, however, are the infections that appear on the outside of the fish, on his skin or fins, such as the sores of ulcer disease, fin rot and mouth rot.  The outside ones are easy to spot and the others lesser so but become easier as the disease progresses. 

More Information About Bacterial Diseases and Infections

• How to Prevent Spring Disease Outbreaks in Koi & Goldfish
• Battle of the Bacteria
• Tricide-Neo Antibiotic Dip for Ulcer Disease in Koi & Goldfish

Bacterial Infections
 and Diseases

Bacterial Gill Disease

Dropsy

Fin Rot

Mouth Rot

Septicemia

Ulcer Disease

Eye Infections

© copyright, 2008, 2009 PondDoc.com.  Reproduction or use of any content on this website prohibited without written consent from PondDoc.com.  This advice is given free of charge and serves as information only to help you with determining the cause of fish health problems.  The content given is to be used as guidelines only.  By following the guidelines on our website you are agreeing that we will not be held responsible or liable for any losses.  We cannot diagnose your specific case.  We are simply forwarding the benefit of our extensive experience with koi and goldfish health.