Category Archives: Bacteria

CASE, KOI: Severe Damage and Ulcer From Pump Intake


Photos and Documentary by Bonnie E. Hale

Lucky came in with a break in his tail. The first night here he was sucked to the pump. The next morning he was found to have a big red colored bulge on his side. The picture below was taken on August 12th 1999.

CASE, KOI: Severe Damage and Ulcer From Pump Intake
CASE, KOI: Severe Damage and Ulcer From Pump Intake


A week later the red disappeared and the real damage was evident. Using small scissors, I carefully cut away the flap of dead tissue. His appetite was good and he was getting along good with the other fish so I left him in the main tank. I did add .3 salt to the tank.

Bonnie E. Hale

This picture shows the full extent of the damage the fish suffered once the flap of skin was removed. On the advice of Erik Johnson DVM, author of Koi Health and Disease, I did nothing but maintain pristine water conditions and salt. The fish continued to make good progress. I was very tempted to do euthanasia on him once I saw how bad the fish actually was.

CASE, KOI: Severe Damage and Ulcer From Pump Intake

CASE, KOI: Severe Damage and Ulcer From Pump Intake
CASE, KOI: Severe Damage and Ulcer From Pump Intake

Three months later all that remains is a small bruise where there was once a big gaping hole. I am confident that he will continue to make good progress.

CASE, KOI: Severe Damage and Ulcer From Pump Intake
CASE, KOI: Severe Damage and Ulcer From Pump Intake

This is Lucky swimming for his picture. You can see the slight indentation where he was sucked to the pump and the knot where there is a break in the tail.

CASE, KOI: Severe Damage and Ulcer From Pump Intake

CASE, KOI: Severe Damage and Ulcer From Pump Intake

Good water, heat and salt.



Bonnie Hale
Code and Graphics edited Dr. Erik Johnson

Day one: The Koi had 5 large ulcers, 2 one side of the tail and the other 2 were on the opposite side of the tail. In addition there were 9 small ulcers that were approximately 1/4″across on the other side of the tail. The 5th ulcer completely took out the pectoral fin. Fluke tabs (Now we use Prazi) and salt to .3 was added the first day. I really did not think this fish would live through the night. I expected that he would pine cone at any time.



Day 3: The ulcer that took out the pectoral fin and socket is now visible. There is now slight healing tanking place in all of the ulcers.


Day8: The koi is making good progress. All flukes are now dead. Salt is at 0.3%


Day12: These are pictures of 6 of 9 smaller ulcers. The koi is making good progress now.


Day 12: The koi is improving greatly now and appears that the antibiotic regime is working.



Day 21: Progress was still being made and recorded on the 21st day. This was the last picture I had taken. Unfortunately, the koi died on the 31stday. All of the 9 smaller ulcers had completely healed. The 5 large ones were approximately 80 percent healed. Autopsy did not reveal anything remarkable.



Fish Tuberculosis or TB Mycobacterial Infections Symptoms and Prevention

Fish may begin to waste away and that is a common sign of intestinal parasites, or fish tuberculosis.

Fish Tuberculosis or TB Mycobacterial Infections Symptoms and Prevention

Fish Tuberculosis or TB Mycobacterial Infections Symptoms and Prevention
TB has distended the Betta’s liver. The fish will lose weight and condition. The liver is full of TB Granulomas

Fish tuberculosis is a mycobacterial infection where the fish ingests the organism via cannibalism and then stores it. The tuberculosis is dormant until the fish undergoes considerable stress. Those forms of stress are identified.

So I made a video that discusses the tuberculosis issue in fish, in detail.

Fish Tuberculosis or TB Mycobacterial Infections Symptoms and Prevention

MelaFix for Superficial Infections in Koi and Fish

MelaFix – Melaleuca Tea Tree Oil

It’s been years since this was written up, and field experiences have borne out the following:

MelaFix for Superficial Infections in Koi and Fish

Melafix remains effective in many of the “garden variety” superficial bacterial ulcers and sores wherein the fish are not “sick” but have scuffs and scrapes in the skin.
The foaming of the product is initially alarming to most people.
A lot of people overdose with this stuff, causing other trouble. Don’t do that.
Melafix 16 OzMelafix AmazonMelafix is INEFFECTIVE against deep or systemic infections or infections wherein the fish are sick and or not eating..

No antibacterial treatment is effective against bacterial infections or sores UNLESS issues with temperature, water quality, crowding, feeding and background pollution have been remedied.

Melafix is a patented 1% mixture of CAS Melaleuca (Tea Tree Oil) which is used to enhance healing in fish.

Melafix is promoted to have antibacterial properties but our research has shown this is not the case. We treated an inhabited system for five consecutive days and then ran CFU (colony forming unit) tests on the water and found a typical population of Aeromonas hydrophila/caviae, and Citrobacter freundii, as well as Serratia spp.

Getting Melafix Right Now

Melafix is promoted NOT to damage the function of the biological filter and this was verified to be true. MelaFix has no negative effect on filtration. We treated a cycled inhabited system and checked daily or derangements in nitrogen reduction and found none during our application period.

MelaFix has no effect on pH. We verified this daily along with other tests of water quality, and everything remained in the ideal ranges.

We have treated numerous species of fish in Atlanta and have found MelaFIx to be nontoxic to all species, including freshwater sting rays.

Koi With Wounds in Our Testing

Within three days, healing was impressive.

We treated daily, using NO OTHER ADJUVANTS or other therapies. The wound was never dressed topically and the fish was never injected. No water changes were done. No SALT was applied or present in test tank water. Within three days, healing was impressive.

  1. MelaFix does not harm the filter
  2. MelaFix does not impact the pH
  3. MelaFix is NOT bactericidal as claimed.
  4. MelaFix (1% Melaleuca) ENHANCES AND SPEEDS HEALING
  5. MelaFix is the most impressive water borne treatment for superficial wounds and bacterial sores I have ever seen.
  6. MelaFix is non toxic to all freshwater species tested.
  7. MelaFix may obviate the need for injections in superficially infected fish.

I will probably add the recommendation of MelaFix to all my cases where a water treatment is practicable and where healing is urgently needed.
Consider MelaFix most favorably in the following conditions:

  • Conditions where many fish are infected and injection is impractical
  • Fish are in small enough bodies of water to be treated economically.
  • Fish have wounds which are lmited to the body, mouth and fins, without systemic or septic signs.
  • Recently handled fish at retail.
  • Fish whose ulcers are “almost healed” but stubbornly will not go away. (Also check nitrates)
  • Fish with breeding abrasions
  • Small species of fish which would not survive or tolerate injection.

Melafix does not harm turtles or other reptiles. Melafix will not clear Ich or any other trematode or protozoan. Ich does not control bacteria but speeds healing. It is possible that positive healing changes in the skin are how the application of Melafix results in improvement of bacterial sores, mouthrot or finrot in affected fish.

My thanks to Aquarium Pharmaceuticals for a 1% and a 5% solutions for testing purposes. Thank you for providing quantities sufficient for replications in at least ten different situations and cases.

Dropsy (Bloater) Pinecone Disease in Koi & Goldfish

“Dropsy” is the condition in which the body is diffusely infected with bacteria and the scales generally stand out from the body. In some, rare cases, generalized scale-lifting is also caused by Costial infection (see parasites) but usually Dropsy is a terminal result of the bacteria attacking the KIDNEY of the fish. Many treatments have been tried with only a less-than-5% percent favorable outcome.

Dropsy (Bloater) Pinecone Disease in Koi & Goldfish

Dropsy, also known as Bloater or Pinecone disease, is usually caused by bacterial invasion of the fishes’ kidney.

Dropsy (Bloater) Pinecone Disease in Koi & Goldfish
Dropsy (Bloater) Pinecone Disease in Koi & Goldfish

There IS also a sporozooan parasite that can damage the Kidney this way, called Mitraspora cyprini, but I have yet to see this on a necropsy.

Dropsy is, for all intents and purposes, untreatable, based on 7 years experience, using the following drugs: Azactam, Baytril, Chloramphenicol, Gentamicin, and Amikacin. I have tried a Sulfa drug, brand name Albon, and that did not resolve the problem either.

Bacterial dropsy is usually caused by Aeromonas or Pseudomonas bacteria. By the time the fish “blows up” and the scales protrude form the body, the damage to the kidney is so profound that recovery is impossible. The reason the scales blow up is because the fish takes on water, unable to expel the water via the demolished kidney.

If you must try to save the fish, isolate the specimen, elevate temps while elevating oxygenation, and begin injecting antibiotics intraperitoneally. You could also feed the antibiotics in a medicated feed.
You read alot about people using Epsom Salts and Peas and a variety of other medications, even Erythromycin with  (supposedly) almost 100% success.

When pushed, they’re unable to present a SINGLE BIT of documentation on their regimen or dosing, and most notably, a SINGLE before-and-after photo. People overstate things. They’re not liars necessarily. But some are.

Dropsy is characterized by the raising of 100% of the scales on the body and BULGING EYES – without ALL scales being raised, and if the eyes don’t bulge, I have my doubts that true Dropsy is present.

The following picture is NOT Dropsy. Note, all scale laying down. This fish is more likely to be egg bound.
Posted on Koivetforum


A Koi With Pinecone or Dropsy from a Small Pond?

This (see above) is a great, great case for us to get to look at. Many thanks to Lynne and her intentions. She is right to decry small facilities and crowding.

I agree that Koi should not be kept in small facilities, at least not for their intended lifespan – whether it causes overt disease, illness, or death is arguable, so have at it -> But whether it does or doesn’t, it’s like raising a Dane in the bathroom. They’re just too big to be truly comfortable.

Or, more simply, if they had a choice to swim around in the 300 gallon, or they could swim through a tube and be in 3000 gallons, where do you think they would be, day in and day out… ?

Louisiana State seems to have worked out the impact of crowding, and there seem to be three factors –

1. psychological

2. physical

3. environmental

And each plays a different part. Their Tilapia work seems to show that when the fish are raised from Fry, under intense rearing conditions they know little else. The physical effects of simply bumping into the walls and each other are negatives that are hard to beat. And the main thing that stunted the growth of the fish was the rapid accumulation of background pollutions like high CO2, rapid depletion of trace elements, rapid accumulation of nitrogen, sagging pH and exhaustion of carbonates.

Constant replacement of water was key.

How close to this, does that 300 gallon pond she mentions, come?

Dropsy (Bloater) Pinecone Disease in Koi & Goldfish

I want you to go back and look at the images again please.

This is not Dropsy.

Please review the images and note the condition of the scales over the caudal part of the body, before the tail…And in the dorsal view, look at the cranial body, behind the head – > Again, NO scales are raised.

Dropsy And Fin Rot

When there is a fluid balance problem, which is what Dropsy is (it’s in the book) -> ALL tissues become edematous and swollen and ALL scales rise.
Later, when people say “I save Dropsy fish all the time!” they’re referring to fish like the one in the picture, but there are extenuating circumstances….

1. Lynne would be hard-pressed to save such a fish because it is in tiny facilities.

I proposed the S.H.I.T. method of saving fish from bacterial methods earlier this month at the University….(Before you jump on me with both feet – it was the after-lunch crowd that is usually sleepy!! And I needed to jolt them up)

When you’re fish get a bacterial infection, and AFTER you’ve assessed the environment, give them S.H.I.T:

a. S – Space

Fish need space to recover…..They will not recover while they are crowded or if conditions of crowding are not reversed. So give them space.

b. H – Heat

Fish do better when their immune system is optimized, and 72-76 seems to be it. Below this, and the fish is “cold” and the immune system is less effective. Above this and the fish is in a heightened metabolic state in water that is less prepared to carry the oxygen demand.

c. I – Injections

When the medicine absolutely positively has to be there overnight – Injections.

d. T – Tricide Neo. (Topicals)

Surface wounds do better and heal faster with it.

2. This fish was on “round two or three” with this.

If it were it’s first time, results could be better in fending off the infection – because the fish is in a strong posture and has not had infection before. After each successive infection, the bacteria, and its damage become more and more indelible in the body.

3. If the scales had been raised all OVER the body, from the head to the base of the tail, Dropsy, and water balance issues would have been diagnosed.

This fish was not destined to survive this. What would have been awesome was a necropsy. If I had to bet, I would wager there was an inspissated egg case in there acting as a foreign body.

If the fish retained eggs and the ovaries became the focus for infection year after year, this would explain why Lyne’s treatments had been effective to a point…

I don’t (or didn’t get from the posts) that we had post mortem information from this case, so that’s only speculative.

What’s the primary cause of egg retention? Infection, lack of spawning circumstances, or too small facilities.

NuFlor Florfenicol Antibiotic Injection

Schering’s “NuFlor” injectable has been used in Europe on Salmonid fishes for a while now. I was introduced to it by my Butler Co. representative in small animal practice. I noticed the name of it: Florfenicol and realized it might be a powerful cousin to Chloramphenicol, which has given us fits in terms of reconstitution, storage, and half life.
NuFlor has since been incorporated into numerous koi cases both here in my clinic, but also in Oklahoma and out on the West Coast, with good success.
Is it a cure all wonder drug? Nope. Read on…

Hello Dr. Eric,
My name is James V. and I am a koi & gold fish farmer. Recently we encountered great problems with Aeromonas ulcers /lesions on our koi and after extensive tests by both Dr. Chris Fouche and Dr. Anna Mouton (Onderstepoort Vet. services) we found that the strain of aearomonas we had (Aeromonas hydrophila ssp.) was immune to most treatments used commonly. Dr. Chris Fouche then reccommended Nuflor as you stipulated in your book “koi health and Disease”. We injected about 860 koi with Nuflor and after only 4 weeks we had 95%of them cured completely ! I just wanted to give some feedback on our experience with the drug for others to see there is always hope, and thank for your contribution too ! Regards James V.

The market is full of commentaries on how Chloramphenicol is the perfect drug. It’s relatively non toxic, it’s safe for even the smallest fish, and it’s readily available for use in non food fish. However, it is not very stable, losing potency within 7 days of reconstitution.

Others tout Baytril [enrofloxacin] as the best antibiotic because it works very well, and perhaps best of all, it usually carries a year’s shelf life and is stored at room temperature. Dr. Greg Lewbart at NC State Raleigh has published alot on it, including a study of it’s efficacy in Pacu. I have preferred it mostly in practice for all the above reasons.

Azactam is off the market.

NuFlor is produced by Schering Co. in large [100ml] tanks. It’s an oil based preparation labelled for use in Cattle only.
I have been injecting koi with this drug via the intra muscular & intraperitoneal route. The drug is reported to be rather irritating to tissues and so, despite my individual successes with it intraperitoneally, I advise you to remain with IM injection until I have evaluated actual peritoneal tissue responses in test fish given IP injections. See note at conclusion, below. There are two intramuscular routes available and they are illustrated photographically on Koi in my new book, “Koi Health & Disease”.
I have also injected the compound into Koi via the intraperitoneal route, and to my surprise, have had no losses that way.
I have noticed that the best response is had when Koi are injected early in the progression of the bacterial infection. If the Ulcers are small, or the mouth is incompletely damaged, a single shot of Nuflor will resolve a pleasingly high number of cases. I theorize that because the product is oil based, it is more slowly absorbed and therefore it fails to intercept cases which are “on the way out”. However; the oil based nature [and extended release] of the drug makes it ideal for conditions wherein repeated injections might be laborious or impractical.

Nuflor has been tested by Gary Cryer at Koi of Oklahoma and he is impressed with the results in general. His results are similar to mine in that he noted that fish that were on their way out did not recover, whereas the fish with more manageable lesions went ahead and recovered nicely. Gary will be testing some newer ideas for me at his location, including an immune stimulant and some other injectibles that hold alot of promise. Keep your eye on my site and visit his for more information from time to time.
Several breeders and importers in California are also enthusiastic about NuFlor’s extended storage time, and the concept of a single injection resulting in complete recovery.

We are using a larger needle to inject the drug. Nuflor is oil based and therefore is drawn up into a syringe with a 20 guage needle. Injecting the drug with a 22 guage or smaller usually results in an extended injection time, and more potential for damage to the fish with the struggle. I am injecting IM & IP with a 20 guage needle.

Even though Nuflor is three times more potent than Chloramphenicol (300mg/ml versus Chloro’s 100mg/ml) I am using the old Chloramphenicol dosing chart. The idea is that since the compound is more slowly absorbed, and released more slowly, then there should be an additional amount to provide quick loading and long term availability. Studies to trace the pharmacology of this drug would cost over $10,000 and are not entered into lightly by institutions.

Use of NuFlor 300mg/ml injection is detailed in chart below

I have had a single fish develop a visible complication after injection. A single fish developed a blisterlike sore over the site of injection in the muscle, which will probably leave a noticeable scar. I have injected more than three dozen fish* (1998), some as small as 5 inches, with no untoward reaction or lesions.

I am preparing to perform some trials with NuFlor via the IP route, and grossly observe the peritoneums/abdomens of these fish one and two weeks later to establish or discount the formation of untoward adhesions or inflammation.

Update: 3/15/98
Since we started using it, we’ve put alot of Nuflor into use. It’s bruising some fish injected IM but it’s been found to be very safe injected in the peritoneum. The bruising in the muscle is temporary and lasts three weeks. The efficacy of Nuflor on ulcer disease is very good.

NuFlor is available from your local fish-friendly veterinarian, if you can find one. Tell them about this site, so they can become useful to you and to your fish. If you are unable to obtain a medication you need, send me an email and I will provide you with the needed information on how to obtain it.

Dosing Nuflor 300mg/ml – INTRA MUSCULAR

“Okie Dokey. The above article is pretty old. Lots of people have been injecting NuFlor into the muscle and many more still have been using it IP, or into the belly (intra peritoneally) without harm.

I am reluctant to use it on large Kohaku’s because of a rare reaction in which the fish will turn bright red, and some of them will die. We do not know if it’s a cellulitis or a sensitivity to sunlight. It has only happened in red and white fish – and some of the Black and white (shiro) variety. But I have had about three fish among the hundreds injected, to turn red and nearly die after Nuflor injection by the IM route.” ~ Doc Johnson

Baytril / Enrofloxacin Dosing Injectable in Koi and Pond Fish

You can use Enrofloxacin up to three days apart against bacteria susceptible to its effects.

Baytril: (Enrofloxacin) Injectible is usually a 2.27% solution.

I have used this with success in cold water.

Do not inject the ovary in gravid females as the drug will not be absorbed efficiently. Gravid females are good candidates for intra muscular injections.

Baytril need only be dosed every other day, or even every third day in most fish. This is new information.

Recommended dose, (I. ictaluri) is 14mg per kg.

I give the drug Intraperitoneally, with a 25 G needle on a tuberculin syringe.

Fish Length in inches
Volume Baytril in ml.
6 inch
0.1 ml
10 inch
0.3 ml
14 inch
0.6 ml
18 inch
0.9 ml
22 inch
1.0 ml
26 inch
1.25 – 1.50 ml
1.75 ml
2.0 ml

Be careful injecting gravid (egg laden) females. The antibiotics will simply go into the egg mass and will not get diffusion throughout the body where needed! Better in those to inject IM (Intra Muscularly)

Bacterial Infections @ Finrot in Fish for Retailers

Pet store owners — this is for you. Bacterial Infections @ Finrot in Fish for Retailers

If and when you see fish with rotting mouths, fins, and skins, it’s bacterial. You can also safely assume that the fish have parasites because *that’s* how the bacteria got from fish to fish!

There are four concepts to understand concerning fin rot.

First, finrot is usually a bacterial infection which results from any one of four causes,
1. Fin nipping
2. Parasites like Flukes or Ich inoculating pathogenic bacteria into the skin
3. Deteriorating water quality, inadequate filtration, or high bacterial counts in the water because a hobbyist is not using an undergravel plate and the gravel bed has become stagnant.
4. Poor nutrition

Second concept:
To recover fish, water quality must be corrected even if you start using antibiotics to kill the primary bacterial invader. Remember that most any treatment you might use for pathogenic bacteria will likely also affect your nitrifying (filterbed) bacteria and this can, in loaded systems that are already barely keeping up, cause Ammonia or Nitrite accumulations.

Third Concept:
Treat in a hospital tank. A ten gallon with a hood, a heater at about 78 degrees, and a sponge filter all cycled and ready. Treat with Trimethoprim Sulfa 960mg in ten gallons of water made fresh daily for 6 hours a day for three days. Alternative drugs would be any of the Furan antibiotics (Furazone Green® is excellent) or even possibly, as a very last resort, Maracyn from Mardel “Labs”. Treating in the main system will land you in new water quality problems because most medications that kill bacteria on fish also kill nitrifying bacteria.

Fourth Concept: 

Nutrition is best supplemented with live or fresh frozen foods fed from a basket feeder. How you feed it makes a difference because from a basket feeder, there is little waste, and fewer food morsels are lost in the tank, therefore water quality does not deteriorate, bacterial numbers do not skyrocket, and fish are capable of recovery. Good choices are frozen Brine Shrimp Plus, or plain brine shrimp, blood worms or maybe Prime Reef.
So, for finrot, consider an overhaul of the system to optimize water quality. Consider removing affected specimens to a hospital tank and treating there. Consider a basket feeder and varying the diet.

Humans May Contract Aeromonas Infections From Koi and Pond Fish


May 25, 1990 / 39(20);334-335,341

Aeromonas Wound Infections Associated with Outdoor Activities — California

Aeromonas species are associated with gastroenteritis and with wound infections, particularly wounds incurred in outdoor settings. On May 1, 1988, isolates of Aeromonas became reportable in California, the first state to mandate reporting of isolates of and infections with these organisms. Surveillance data for 1988 and 1989 represent the first population-based estimates of both the occurrence and public health impact of Aeromonas infections in the United States and provide a basis for assessing the need for further surveillance of these organisms.

From May 1, 1988, through April 30, 1989, clinicians and clinical laboratories in California reported 225 Aeromonas isolates from 219 patients. Cases were reported on Confidential Morbidity Report cards to local health departments, which then conducted case investigations and forwarded their reports to the California Department of Health Services. Of the 225 isolates, 178 (79.1%) were recovered from stool, 19 (8.4%) from wounds, 11 (4.9%) from blood, and 17 (7.6%) from other sites. A. caviae was recovered from seven stool cultures; A. sobria was recovered from two stool cultures and one vaginal culture. All other cultures were reported as A. hydrophila or Aeromonas unspecified.

Based on reported cases, the incidence of Aeromonas wound infections in California was 0.7 per million population. Of the 19 patients with wound infections, 13 were injured outdoors (Table 1). Six of these patients required hospitalization for their injuries and/or infections. One patient had a mixed infection including Aeromonas, Proteus, and Pseudomonas species. The number of infections peaked in the summer months with three cases each in July and August. The cases reported among persons aged 30-39 years represented the highest incidence rate for all age groups (1.4 per million). Reported by: SB Werner, MD, Infectious Disease Br, GW Rutherford, III, MD, State Epidemiologist, California Dept of Health Svcs. Div of Field Svcs, Epidemiology Program Office; Enteric Diseases Br, Div of Bacterial Diseases, and Epidemiology Br, Hospital Infections Program, Center for Infectious Diseases, CDC.

Editorial Note

Editorial Note: Aeromonas species are gram-negative, facultatively anaerobic bacteria found in soil and fresh and brackish water worldwide (1). Although Aeromonas species were recognized in 1891 as colonizers and pathogens of cold-blooded animals, especially fish (2), they were not identified as human pathogens until 1968 (3). Since then, they have been associated with a wide spectrum of human diseases (especially in immunocompromised patients), most commonly gastroenteritis (4) and soft tissue infections (5).

The taxonomy of Aeromonas species requires further clarification. Three species, A. hydrophila, A. sobria, and A. caviae, have been associated with human disease (4), but DNA hybridization analyses support seven or more distinct genotypes (6). Because many clinical laboratories are unable to perform precise identification, many aeromonad isolates are reported as A. hydrophila or A. hydrophila complex. Although the California surveillance data provide limited information about the morbidity of the wound infections reported, they suggest that the public health impact of these soft tissue infections is low and may be determined more by the nature of the underlying injury than by the presence of Aeromonas organisms.

The California data do not provide information on case management. However, one reported case series (7) suggests that surgical debridement is an important component of treatment and has enabled resolution of the infection when either no antibiotics or ineffective antibiotics (i.e., antibiotics to which the organisms were resistant) were used. These findings, as well as the occurrence of Aeromonas organisms in mixed infections, suggest that in some cases Aeromonas species may be colonizers in wounds rather than pathogens.



Von Graevenitz A. Aeromonas and Plesiomonas. In: Lennette EH, Ballows A, Hausler WJ, Shadomy HJ, ed. Manual of clinical microbiology. Washington, DC: American Society for Microbiology, 1985:278-81.

Ewing WH, Hugh R, Johnson JG. Studies on the Aeromonas group. Atlanta, Georgia: US Department of Health, Education, and Welfare, Public Health Service, Communicable Disease Center, 1961.

Von Graevenitz A, Mensch AH. The genus Aeromonas in human bacteriology: report of 30 cases and review of the literature. N Engl J Med 1968;278:245-9.

Holmberg SD, Schell WL, Fanning GR, et al. Aeromonas intestinal infections in the United States. Ann Intern Med 1986;105:683-9.

Janda JM, Duffey PS. Mesophilic Aeromonads in human disease: current taxonomy, labo ratory identification and infectious disease spectrum. Rev Infect Dis 1988;10:980-97.

Popoff MY, Coynault C, Kiredjian M, Lemelin M. Polynucleotide sequence relatedness among motile Aeromonas species. Curr Microbiol 1981;5:109-14.

Isaacs RD, Paviour SD, Bunker DE, Land SDR. Wound infection with aerogenic Aeromonas strains: a review of twenty-seven cases. Eur J Clin Microbiol Infect Dis 1988;7:355-60.

Tricide Neo tris-EDTA Solution Against Bacterial Infections

To nutshell this for the 2019 user, I love this stuff made up in a gallon jug of DISTILLED water. Fill a spray bottle with that mix. Put fish to be treated in a large plastic fish bag. Spray the Tricide Neo into the bag til the fish are just covered in the stuff. Leave them in the bag until you start to worry about them. Or three minutes.  Put the fish back into the water.

Tricide Neo tris-EDTA Solution Against Bacterial Infections

Tricide Neo – Antibacterial Dip is AMAZING – by Dr. Erik L. Johnson

Tricide Neo
This is kind of a long story but I will try to keep it to the nuts and bolts. In fact, I think I’ll kick it off with an “abstract” for those of you on a time schedule, see the inset box immediately below.

Premise: People dislike doing, (or cannot get) injections of antibiotics for bacterial infections in Koi and Goldfish.
Fighting infections involves correcting or optimizing environmental conditions but definitely also includes starting some sort of antibacterial therapy.
Tricide Neo fights infections like nothing else out there. Tricide Neo arrives as some crystals in packets. Theres a one gallon and a five gallon size. You dissolve the crystals and then simply dip or spray the fish with the solution. It can be re used, and it’s stable for over a year in solution. It’s simpler to “dip” fish to recovery. On the downside, this is very powerful medicine and will kill your beneficial bio-filter bacteria if it’s allowed to get back into the main pond on the fish*. So, rinse the fish in a clear water rinse before replacement in the main facility.

*It takes a pretty good bit of Tricide Neo to harm the filter. But in a 100-200 gallon hospital tank it might matter.

Dr. Johnson’s Opinion: Tricide Neo Dip is excellent. Nothing I have seen comes close to this breakthrough in the treatment of Ulcer disease, fin rot, or especially mouth rot when injections are not feasible.
Recommendations for perfect deployment:
A Tricide Neo dip COUPLED with a high quality, heavily-medicated food should ‘do the trick’ in nearly 100% of bacterial infections. In other words, Tricide Neo and [medicated food unavailable due to FDA] would be where I would stake my reputation.
Is Tricide superior to injections? From a legal standpoint, yes. But from an efficacy standpoint, No. But I might offer that Tricide is performing just as well as injections, or certainly “as close as you could get” to their effectiveness. Far superior to any “antibiotic” dip (such as Furazone) which I at one time had a higher regard for.
Background: In the summer of 2002 I started hearing about a “Vicki Burnley” from the University of Georgia. I wondered, who is this person? Without more details available, I just thought nothing more of it.
Then I had a case in Marietta I was house-calling, a pond full of super-fine Japanese imports which were dying, and breaking down with body sores, gill rot, and other disorders stemming from bacterial infection. We injected all the fish, fed medicated food, and improved water quality as much as we could. The fish continued to die.
Three weeks into the disaster, Vicki Burnley was addressing the Atlanta Koi Club at this residence and as part of her presentation, she administered Tricide Neo dips to the Koi patients.
On my return to the pond, the customers came out and indicated all the fish swimming around. Two straggler fish, too poor to be saved were destined to go on and die but the rest had made an amazing recovery. I was stupefied. And so I searched out this Vicki Burnley and introduced myself. As a result, I was invited to University of Georgia to see the Aquaculture operation she is working on there, and I met the gal. She’s great. I found her personable and not at all “on a high horse.” She shared with me everything I wanted to know about the Tricide Neo and how it works.
Since I was introduced, I’ve sent Tricide Neo on quite a few test cases and all of them come back with glowing reviews. And no more shots of antibiotics.
What is it?
Tricide Neo is a concentrate of NeoMycin (although many different antibiotics could be potentiated) with an antibiotic potentiator. The folks at Molecular Therapeutics say it best so I will quote them:

“The antibiotic potentiator in Tricide-Neo has a rather interesting mode of activity that facilitates its spectrum of activity. Tricide-Neo creates holes (Figure 2) in the bacterial cell wall which in-turn allows antibiotics to flood the organism, destroys the effectiveness of the bacteria’s efflux pump and facilitates osmotic collapse of the bacterium. Because the potentiator causes direct physical damage to the bacteria, one is able to use less antibiotic than would normally be necessary and exposed bacteria are less likely to develop resistance to the chosen antibiotic.”

Basically, the chemical base of Tricide Neo knocks holes in the bacterial cell wall while sparing sensitive fish tissues. As if being perforated would not kill the bacteria, there’s Neomycin in the mix to kill the bacteria through these pores in the cell wall.
What you get is a packet of dry crystals. Helpfully, the Tricide-Neo packet is covered in instructions and is easy to use. More on this later. You open the packet and dump the crystals into either a one gallon jug of distilled water, or a five gallon pail or tub with distilled water in it. Once the crystals are dissolved, the fish are processed through the tub for anywhere from four to seven minutes*. After the dipping; the fish should be rinsed off in a post-dip of pond water, and then replaced in the pond or hospital tank.

*The above was the original packaging and the way they used it in their studies. But it ended up with a cooler full of pink bloody mucusy water from all the sick fish going through it. So I came up with the Spray in the Bag method. Three minutes.

What’s It Good At?
Tricide Neo is excellent at curing bacterial infections such as fin rot, mouth rot, and body sores. Internal infections are not reached by Tricide Neo and this is why I strenuously recommend the use of a medicated food with it, when treating these type of internal infections.


Tricide Neo was used in the fish at left, belonging to Mike and Jennifer. Availability of antibiotics in the form of injections is limited and promises to become more so; over the next couple years. Especially with mouth rot, the fish is unlikely to want to eat with the sore mouth, so the efficacy of medicated food becomes limited.
This fish belongs to Mike and Jenny and they treated the fish with Tricide Neo and recovered it. Amazing results for an antibacterial dip.
Anyone with a stop-watch should be able to do this with success but there are some precautions, the most common mistake is being the use of contaminated dip. For starters, you can’t mix Tricide up and use it on two or three different groups of fish because you could transmit diseases between groups. All fish in ONE pond can be treated with no risk, but you would not carry that dip down the street to a neighbor’s house. (This is beat by the Spray in Bag method)
If the fish bleed in, or “slime-up” the solution, it needs to be preserved before it’s next use the following day. Some folks have put it through a coffee filter or an un-dyed terrycloth towel to remove as much cellular and organic slime-debris as possible, then refrigerate. (This is beat by the Spray in Bag method)

Tricide should be brought to an accommodating temperature before use the next time, so as not to shock the fish.
You should check the pH of the solution before every use if it’s being used as a dip for lots of fish. (This is beat by the Spray in Bag method)

“Dip Quality” is hard to maintain when there are a lot of fish being run through the dip solution and the dip tank needs to be aerated heavily.

Spray Method.
You can mix up a solution of Tricide Neo and spray it on. Simply mix up the solution and put some of your gallon-mix in a small sprayer bottle and put the fish in a plastic bag and then spray the fish on it’s wounds, with the Tricide. What’s the advantage? You can use less Tricide this way, and also, hopefully, not have to use the Tricide over again the next day. REASON: A fresh sprinkle or misting of brand new Tricide for a few minutes would be superior to a stale dip the next day, if it’s economically feasible.
The Shake and Bake Method
Is essentially the same as the above Spray method except that you would simply place the fish in a plastic bag and then pour in just enough Tricide Neo to cover the fish and allow gill coverage for it to “breathe” – leave the fish in the solution for a three to four minute dipping and then move the fish to clean fresh water. The Shake and Bake bag can be reused until it looks “nasty” and then a new bag prepared. Again, the advantage is in “not sullying” your whole dip container, and just using a little new Tricide Neo on each fish until you run out.
Normal Tub Method
You’d simply mix up the crystals in distilled water, fill a one gallon tub or a five gallon tub depending upon what you’ve bought, aerate it, and then dip the fish in there for about four minutes. When the dippings were over you could try and clean the solution by pouring it through an inert textile like polyester fiber fill, coffee filter, or an undyed cloth. Then refrigerate the solution for use later.  (This is beat by the Spray in Bag method)
DO NOT re-use any solution on a different group of fish in case you should transmit an undetected or unknown pathogen from one group to another.
It’s simple to dip a fish for four to five minutes. Solution has a long shelf life before and after reconstitution. Solution can be sprayed on, or “Shake and Baked”
If fish are left in Tricide Neo solution too long, they will suffer skin, fin and gill damage. If the solution fouls, it must be replaced. Using fouled or contaminated solution can hurt your fish but your eye and nose can tell if the solution is “good” anymore or not.

At retail:
There are quite a few sites which offer Tricide Neo for sale and you should be seeing more and more of it on dealer’s shelves as well. Thank gosh for Google!  LOL

Dr. Erik Johnson is a veterinarian and has kept fish as pets since 1973
This article is not authorized by Molecular Therapeutics and is not written with their permission. It recounts my introduction to Tricide and my clinical impressions.

Why Culturing The Outside of the Koi is Poor Diagnostically

Bacterial cultures taken from the outside of the fish, or directly from the ulcer can be badly misleading because you’re collecting germs from the fish and the water column.

When you biopsy the fishes’ surface, you biopsy the fish pond. What’s ON the fish is a mix-n-match of every bacteria in the pond is NO commentary on what is actually IN the fish, killing it.

The following video discusses this concept and I hope, describes the important idea of culturing the kidney in a sacrificial fish, or culturing blood taken from the caudal peduncle.