Ulcer Disease

If you see a red sore that is not the coloration of your koi or goldfish either just below the skin of the fish or open and "ugly", your fish most likely has an ulcer.  Upon further examination you might see more suspicious-looking areas.  Ulcers are very dangerous and, though they are known to heal without our intervention in a small percentage of instances, they most often end up in death of the fish.

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

Ulcer disease in koi and goldfish is caused when bad bacteria invades the skin of the fish and sets up infection.  Often it is a secondary problem that occurs after a bout with parasitic infestation.  Flukes are notorious for carrying anaerobic bacteria and as the flukes create tiny holes in the skin of the koi or goldfish the opportunistic flukes use these passages to get inside the soft skin tissue.  A tear in the skin or injury can become infected and ulcerated as well. 

Overcrowded ponds (which most of us have) and ponds that provide optimum conditions for bad bacteria to breed (junk in between rocks on the bottom of the pond and low aerated areas) will most often experience problems with ulcer disease.   

Recognizing Ulcer Disease

The sooner you recognize an ulcer on your koi or goldfish and treat it the better off the fish will be.  Ulcers begin to appear as sometimes very small, sometimes very large red blotches that look like a sore just below the surface of the skin.  As they progress the scales will fall off or loosen on and around the ulcer and the skin will break apart.  In advanced cases large gaping holes will grow and get larger.  The fish usually will die if the ulcer gets too far advanced.

	The ulcer on this kohaku is barely noticeable against the red coloring of the koi.  Notice, though, that the coloring of the ulcer has the appearance of an infected sore.
	Here is an excellent example of an advanced case of ulcer disease.  Believe it or not, all the koi pictured on this page were treated with Tricide-Neo and their ulcers were healed!

If the sore isn't red and is milky-white in appearance, perhaps even raised and/or appears to be jelly-filled, chances are this "sore" isn't an ulcer at all.  It may be carp pox which, although it's not attractive, it will not kill the fish.

Treating Ulcer Disease

First you must find the cause of the outbreak.  If you have recently added fish to the pond and did not treat and quarantine the new arrivals prior to introducing them into the pond you may as well assume that parasites are present and are the probable initial cause.  Treat with a parasite pak.

Once those treatments are over you can begin addressing the bacteria in the pond.  Bad (anaerobic) bacteria is present in all bodies of water though some ponds are more ideal for breeding it.  It's not a bad idea to treat the whole pond with a bacterial treatment such as FuBa Fix if you suspect that your koi or goldfish are breaking down with ulcers.  Remember not to allow any bacterial treatments to flow through your biological filter or you will end up without a functioning nitrifying cycle.  Bacterial treatments do not differentiate between good and bad bacteria.    

Once the disease becomes an ulcer simply sterilizing the pond of bacteria will not always cure the ulcer.  For those fish that show advanced ulcers (breaking the skin) a topical scrub or dip is recommended though it's also good to attack it at the earliest sign of an ulcer.  The best thing we've found for ulcers is Tricide-Neo Ulcer Dip.  Unfortunately some fish are just too weak to withstand the harsh treatment.  For those fish we have Lil' Dab-a-do Ulcer Scrub.

Advanced koi hobbyists will often inject their prized koi with antibiotics.  These must be prescribed by a qualified veterinarian.  Often, though, we've found that Tricide-Neo and/or Lil' Dab-a-do will do the trick. 

You must be able to handle the fish every day for about a week so if you have a hospital tank it will make the treatments a whole lot easier on you and the fish.  You need not quarantine any fish with an ulcer (unless you have the availability of a hospital tank) because unless a fish's immunity is weak (or there are other stress factors going on such as water parameters are bad or parasites are present) he shouldn't break down with ulcers by simply swimming with an infected fish.

Start feeding your fish with triple antibiotic food and only the medicated food for about 2 weeks.  Then stop.  This will insure that you are attacking the infection from inside as well as the outside of the fish.

Emergency Procedures

1. Take steps as soon as possible to get rid of the cause of the outbreak (parasites?).
2. Begin treatment immediately on any fish that shows an ulcer with either a dip (Tricide-Neo) or Lil' Dab-a-Do Ulcer Scrub -- (or if you are able, a series of injections - see your veterinarian for assistance).
3. Begin feeding with triple antibiotic food.

What to Expect Next

You may see fungus or "fuzz" on the skin around the ulcer.  Fungus feeds off the dead tissue that the ulcer creates.  You can get rid of the fungus by using FuBa Fix (which also doubles as a bacterial treatment).  You will know the ulcers are healing because they begin to turn white.  Sometimes the scales will grow back but not always.  The ulcer can certainly leave a scar that may never go away. 

Notice that the ulcer on the tail of this koi is turning white.  The ulcer is not healed completely until it shows no more red.  Though not out of danger yet, this koi is on its way to being healed of the ulcer and, in this case, Tricide Neo dips will continue for a couple of more days.

Preventing Ulcer Disease

Sometimes even the best of us have problems with ulcer disease no matter how diligent we are about keeping the pond healthy.  Overcrowding is always a problem (even in our own personal pond) because we all tend to have too many koi and goldfish and ulcers can occur simply because of that.  Keeping the pond clean is a must for koi ponds.  Not lining the pond with rock will prevent junk from settling in between the crevices and becoming a breeding ground for anaerobic bacteria.  Keeping the fish healthy is the trick to fighting ulcer disease.  We like to treat our pond for parasites first thing in the spring as a precaution.  We also feed them triple antibiotic food at the same time.

More Information About Ulcer Disease

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

Items You Might Need:

Tricide-Neo

Lil' Dab-a-Do

FuBa Fix

Triple Antibiotic Food

Know Your Gallons!

Heavy Duty Water Meter

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