Bacterial infections: what you should know

Also: Finrot, mouthrot, body sores.

Ulcer Disease is almost always caused by Aeromonas bacteria or more rarely Pseudomonas bacteria. Clinically, I wouldn't know which because I rarely culture the pathogen. Why not? Because the results could take a week to return, and by that time, all the affected specimens would be dead. I have treated ulcer disease with the following drugs: Enrofloxacin, Chloramphenicol, Gentamicin, Amikacin, Tetracycline, and recently, Azactam. I inject these drugs.

No discussion of this problem would be complete without reference to swabbing techniques, antibiotic enriched feeds, injection technique, and prognosis. Provided elsewhere are drug dosing information, etc, needed to enhance your understanding of this disease.

Suffice it to say, that to save these fish, my core recommendations would be to get the fish into a heated environment, provide impeccable water quality, swab the wounds with Iodine or Mercurachrome, Feed MediKoi 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.

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

Koi with Ulcers