No discussion of this problem would be complete without reference to swabbing techniques, medicated fish food, injection technique, and prognosis. Provided elsewhere are drug dosing information, etc, needed to enhance your understanding of this pond fish bacterial disease.

Suffice it to say, that to save these pond fish, my core recommendations would be to get the koi fish into a heated environment, provide impeccable water quality, swab the wounds with Iodine or Mercurachrome, Feed Medi-Koi feed, inject Enrofloxacin and or Chloramphenicol, and hope that the next spring that the fish does not bloat due to retention of latent bacteria in the kidney after clinical cure.If you cannot obtain injectable antibiotics or do not want to inject your koi, Ulcer Aid Rx is the treatment for you. Ulcer Aid Rx is the second best treatment for deadly pond fish bacterial infections like tail and fin rot and koi body sores. With Ulcer Aid Rx you just spray, dip or bathe your sick pondfish, easy and fast!!

Flukes are the most common carrier and cause of koi and pond fish ulcer Disease. 

Fish Medicines
Learn about fish medicines, what they do, and where to get them.

PondCrisis.com
If you have a koi, pond or fish problem, this site takes you through twenty easy questions and at the end you know what you need to fix in your pond to create restored Koi health.

KoiCrisis.com
Koi Crisis has a symptoms chart by system you can choose the symptom by fish part, and resolve a lot of Koi pond fish problems or at least, learn about them understand how to remedy them.

Koi Food & Feeding
What should you feed your koi? How many times per day? Is Corn really that bad in a Koi diet? What are the most common feeding mistakes people make? What's the best food?