Bacterial Gill Disease (BGD)

Bacterial Gill Disease is a deadly disease that affects the gills of koi and goldfish, making it difficult for the fish to process oxygen.  It is contagious and tends to affect populations that are overstocked and where poor water quality exists.  It can be brought on by gill flukes but not necessarily.

How to Recognize, Treat and Prevent Bacterial Gill Disease in Your Koi or Goldfish Pond

The only symptom koi and goldfish who are infected with bacterial gill disease may show is a need for more dissolved oxygen in the water - and, of course, they may die.  Fish who are starving for oxygen will gulp at the surface gasping for air or hang around the fountain or waterfall, wherever water is falling into the pond and creating bubbles.  There are other reasons a koi or goldfish might display these symptoms like ammonia or other water problems, gill flukes or that the pond simply doesn't have sufficient dissolved oxygen.  These other possibilities should be considered before coming to the conclusion that your fish have bacterial gill disease because BGD is not as common as the other ailments.

Recognizing Bacterial Gill Disease

A quick look under the gill plate will show whether or not the gills are in trouble.  If the gills are torn, uneven, scarred, discolored or look like hamburger meat that tells us that the gills have undergone trauma and it also indicates bacterial gill disease.  Ammonia can cause "clubbing" of the gills which is permanent damage but bacterial gill disease will damage the gills much worse.  Healthy gills should be beet red, have even edges in perfect semi-circles and should not have spots of discoloration.  The edges of an unhealthy gill may look like the edges of a feather with chunks out of it and white streaks through it.  Grey spots are masses of dead tissue and you can see that illustrated in the picture above.  White on the edge of the gill indicate ammonia, nitrite or pH crash burn and isn't an indicator that the fish has bacterial gill disease.   

	This koi died from BGD.  Notice how the gills are striped with white, a sign that flukes had something to do with him getting BGD.
	This large fancy goldfish is still alive but was unfortunate to be in a tank with others that were suffering from Bacterial Gill Disease.  We found the disease before it killed many of the goldfish.  Notice how the gills resemble hamburger meat.  We will treat the whole tank of survivors but every goldfish in his tank will forever have delicate gills and will need to be in  a well-aerated, healthy and clean environment to be able to live happily.

Treating Bacterial Gill Disease

If the BGD is caused by gill flukes the flukes must be treated to stop the cause.  If you don't have the availability of a mucus scraping (biopsy) to see if gill flukes are present on the gill tissue you should assume that the fish have flukes and treat first with either Fluke Tabs, Anti-Fluke or Prazi Pond.  Then, after the fluke treatment is performed you would then treat for BGD.   There are specially formulated medications used to treat Bacterial Gill Disease.  We use BGDX by Argent Labs.  You will definitely need to bypass your biological filter while treating with BGDX, otherwise it will kill the nitrifying bacteria in your filter.

It's also not a bad idea during the treatment time to feed the fish triple antibiotic food.

Emergency Procedures

1. Insure that there is adequate aeration in the pond or treatment tank.
2. Treat the pond for flukes if gill flukes are suspected.
3. Treat the pond with BGDX - be sure to bypass the filter.
4. Feed triple antibiotic food during both treatments.

What to Expect Next

The gills of any surviving fish will be scarred from the incident and may not ever return to full working capacity.  We suggest adding an aeration pump and air diffuser to the pond to give the survivors a more oxygen-enriched environment. 

Preventing Bacterial Gill Disease

Excellent water quality is probably the one best thing we can have to prevent bacterial gill disease.  A pond can never have too much biological filtration.  Make sure the filter you have is sufficient (and even more than sufficient) for your fish load.  We use the ProBead because it gives us excellent water quality and low-maintenance.  Try not to overstock the pond though we know how easy it is to do!   

Keep bad bacteria like aeramonas and pseudomonas at bay by not supplying them with a fertile breeding ground.  Don't line the bottom of the pond with rocks where organics can accumulate and keep the pond clean, well-aerated and circulated.

More Useful Information

• Battle of the Bacteria

Items You Might Need:

BGDX

Prazi Pond

Fluke Tabs

Anti-Fluke (Life Bearer)
 

Air Pumps & Accessories

Triple Antibiotic Food

ProBead Biological
Bead Filters

Know Your Gallons!

Heavy Duty Water Meter

© 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.