Metronidazole Discussion

[triscuit]

I've read a few times on the ACA boards that the only effective way to administer metro is with food. :unsure: I would say that's great when the fish are still eating, but that even in high pH, hard water, with fish that are no longer eating, metro can be very effective. (Perhaps I'm biased: Clout has only killed my fish when I've used it.)

I have found bloat and wasting symptoms to be effectively treated with metronidazole and Epsom salt combined with fasting.

In fact, I go so far as to recommend not feeding at all, use the Epsom salt, and dose metro heavily (twice a day, 250 mg per 10 gallons, with large daily water changes). I've brought cyps and xenos back from wasting, Victorian Haps and P. saulosi from bloat-like symptoms.

I'd be tickled to hear a discussion of methods of administering metro, both in food and in water, and if there are any references on the efficacy of metro when dosed into the water rather than in food. Thoughts?

[fishmaven]

Melinda,
I know of four ways to administer meds.
1. inject
2. injest with food
3. use drugs that will cross the gill plate barrier
4. add to fw baths in combo with high salt level baths
Somewhere within the disease section there's a discussion about placing fish in a high salt solution and then moving it to a tank water solution that has a med added to the solution. I've used it successfully on plecos and occasionally on cichlids.

In layman terms, I stir as much salt into that bucket as will go into solution. In the fw bath I use tank water and add the med of choice, I soak the fish/es in question in the salt bath until they show signs of distress and then move them to the fw bath bucket. Basically, fluids are sucked from the fish and the tank water recharges the fish bringing in the medicine. When the fish revives and starts to act normally, I repeat the process. Often there's a visible change in the size of the fish even after the first bath cycle. I'll repeat the process until I feel the excess fluids have been removed. I do this daily until results are finalized.

About the meds: Your experience reflects mine in using CLOUT. I don't touch it. I reach for an antibiotic rather than an anti-parasite when treating bloat. Originally chloramphenicol (banished now for fear of people using it improperly) was the recommended drug of choice for bloat in cichlids by Loiselle. I have it here somewhere. In my opinion, met is too strong to use, unless there's no resort. I'd grab ampicillin instead. I don't like leaving the fish in strong meds during the treatment and feel the bucket baths are sufficient. I haven't yet found a study on using drugs this way.
Dan

I've read a few times on the ACA boards that the only effective way to administer metro is with food. :unsure: I would say that's great when the fish are still eating, but that even in high pH, hard water, with fish that are no longer eating, metro can be very effective. (Perhaps I'm biased: Clout has only killed my fish when I've used it.)

I have found bloat and wasting symptoms to be effectively treated with metronidazole and Epsom salt combined with fasting.

In fact, I go so far as to recommend not feeding at all, use the Epsom salt, and dose metro heavily (twice a day, 250 mg per 10 gallons, with large daily water changes). I've brought cyps and xenos back from wasting, Victorian Haps and P. saulosi from bloat-like symptoms.

I'd be tickled to hear a discussion of methods of administering metro, both in food and in water, and if there are any references on the efficacy of metro when dosed into the water rather than in food. Thoughts?

[bobrfish]

Using metro laced food may not be the only method to achieve metronidazole blood levels. However, it may be the best method to administer metro to treatment bloat. Of course if fish are not eating, then this method will not work.

Bloat involves water and electrolyte accumulation in peritoneal cavity (large cavity of abdomen where many organs are found). It is thought that the accumulation is secondary to bacterial and protozoan infection of peritoneal membranes. These bacteria and protozoans enter the peritoneal cavity from the gut.

Normally gut wall keeps bacteria and protozoans out of peritoneal cavity but when certain bacteria living in gut multiply to levels beyound normal gut balance, the immune system neutrophils (cells that find bacteria and destroy the bacteria) attack the gut wall attempting to get at the rapidly multiplying bacteria and protozoans. The result is gut wall becomes inflammed and leaky. Now bacteria and protozoans move from inside the gut to outside the gut and infect peritoneal membranes.

There is evidence that metronidazole will bind to these bacteria and protozoans and stop the multiplication of these organisms. In turn the gut wall is no longer inflammed and gut organisms can no longer enter peritoneum.

To achieve high enough levels of metro at the site where it is needed most would require one of three different methods. One ingestion, two iv administration and third intraperitoneal administration. All three administrations would allow metro access to gut where problem is occurring.

To my knowledge there are no other membranes that will absorb enough metronidazole and deliver enough metronidazole to the site where beneficial effects can be observed.

[fishmaven]

Bob,
So, in your opinion, do you treat the initial infection or the secondary one??
Dan

[bobrfish]

Perhaps one of the first steps that may result in bloat is an intestinal blockage. Following the blockage, various bacteria and protozoans begin to multiple.

If the blockage could be prevented or broken free to move on through gut then bloat would not occur. Increasing the percentage of non absorbed roughage could stimulate gut walls to keep food passing through gut. It is also known that magnesium sulfate (epsom salt) will stimulate smooth muscles of gut wall to move food through gut.

The interesting part is that fresh water fish do not drink water or electrolytes in the water. Fresh water fish are using a lot of energy to keep fresh water from entering their bodies, drinking water would elicit a much higher energy requirement to pump the water out of body.

So, how does epsom salt relieve bloat? If magnesium sulfate would bind to food or mixed with food, that could deliver the salt to site where gut stimulation could occur, relieving blockage.
If epsom salt exerts some other effect on bloated fish, I cannot figure it out.

[bobrfish]

Bob,
So, in your opinion, do you treat the initial infection or the secondary one??
Dan
Metronidazole would treat initial infection as the inital build up of organisms in gut are anerobic bacteria and protozoans.
Once the gut wall is breached, many organisms will be able to infect the peritoneum. Metro and other antibiotics will be required to help save the fish at that point. Other antibiotics would include a third generation cephlosporin, quinolone antibiotic, metro and aminoglycoside antibiotic. This is presuming that no fungal infection or Staph aureus is present.

Rather than dumping the antibiotics into the water, an ip injection of the antibiotics would be of the most benefit. Obtaining and administering these antibiotics is not an easy feat.

[fishmaven]

For me ip injections of met would be a last resort treatment. Let me stress the danger of ruining a kidney with an overdose or treatment for an extended period, even improper placement of the ip. References I've found consider using met as a bath for longer than three days a mistake. I'd think an ip injection even riskier.

I'd be more inclined to grab a true antibiotic, not a chemotherapeutic, and use kanacin if the ampicillin had no influence. Again, these are my opinions. I'm not a vet and can't prescribe drugs. If the fish were eating I'd use met mixed with food. I can't really recommend using met beyond short baths.
Dan

Metronidazole would treat initial infection as the inital build up of organisms in gut are anerobic bacteria and protozoans.
Once the gut wall is breached, many organisms will be able to infect the peritoneum. Metro and other antibiotics will be required to help save the fish at that point. Other antibiotics would include a third generation cephlosporin, quinolone antibiotic, metro and aminoglycoside antibiotic. This is presuming that no fungal infection or Staph aureus is present.

Rather than dumping the antibiotics into the water, an ip injection of the antibiotics would be of the most benefit. Obtaining and administering these antibiotics is not an easy feat.

[DragonKeeper]

Interesting discussion. Lots of information here. Lucky for me I haven't had to resort to metro yet. All my illness problems have been fixed by heat and copious amounts of salt.

[Narwhal72]

Metronidazole is the drug of choice when treating peritonitis. I myself have had it after a ruptured appendix. The trade name in the health care industry for it is Flagyl.
Bob is right on the money. Although the metro. does not treat the initial cause of the infection it is necessary if you wish to save the fish. Once peritonitis sets in and the protozoans begin destroying organ tissue the fish will die even if the original intestinal blockage is cleared without treatment.
The best way to administer for peritonitis treatment would be an intraperitoneal injection however with small fish like cichlids this can be very difficult and just acquiring the needles and liquid medication (since metro is sold over the counter as a tablet or powder) may require the assistance of a vet.

There are lots of good how to guides on injection on koi hobbyist sites where this practice is more common. It works a lot easier with a nice big koi. Here is one.
http://www.lonestarkoi.com/Articles/needles.html

Andy

[triscuit]

I'm not yet convinced that these intricate methods are necessary when many folks have had success treating bloat-like symptoms with metro in tank water. The severity of infection and speed of treatment are of course factors, but why try to inject or do high-stress baths if simpler, less invasive methods are effective?

I am not a ichthyologist, so my understanding of fish physiology is limited. But, the number of successful treatments using metro dissolved in tank water leads me to conclude that sufficient metro is absorbed by the fish to kill disease organisms.

[chc]

"Correlation is not causation."

I've "cured" more fish with stepped up water changes than I have with meds. Truth is, bloat is a catch-all term to many hobbyists, so it's tough to make close comparisons when disease diagnosis is primitive at best for most people.

Also, it's tough to tell when a fish's own immune system was tough enough to save it or when meds were the cause -- especially in home aquaria and in the absence of true scientific methods of control and analysis.

Bob's response is excellent. As I remember, there was an article in a BB a few years ago about this topic. I could be wrong (Cichlid News perhaps?), but I seem to remember there was...

[tjudy]

I recently battle bloat... extreme bloat... in some T. dubiosi. One fish was so bad that it was losing scales. There is a lot of evidence in veterinary reports that the primary cause of bloat is Hexamita populations in the gut. Any bacterial infection would be secondary to those protozoans. I used metro, increased concentration of magnesium sulfate (epsom salts) and water changes on the main aquarium, but I removed the two most obviously infected fish to hospital tanks. I found a report by a veterinary student at Va. Tech. who successfully treated Hexamita infestations in angelfish (Pterophyllum) by using a micropipette to force a 3% magnesium sulfate solution into the fishes' guts through their mouth. I did that with the tropheus and both fish are now cured and back with the colonies. These fish were so bad that everyone who saw them encouraged me to euthanize them.

Since then I have started making a 'medicated' gel food preparation using magnesium salts instead of metro. It takes more gelatin in the mix because the salts make it harder for the gelatin to set up. I start with a 1.5% by mass salt solution and then use it for the recipe. I feed that gel food a few times each month as a preventative. So far I have not had any problems.

I also use the salted food to feed all the fish in my fish room that are traditionally 'at risk' of hexamita-related infections like lateral line erosion and HITH. (I have some oscars and some SA eartheaters.)

Here are some references for those of you who will ask for them. :lol:

Management of Hexamita in Ornamental Cichlids http://edis.ifas.ufl.edu/VM053

Andrews, Chris, Exell, Adrian and Neville Carrington. 1988. The Manual of Fish Health. Tetra Press, NJ. 208 pp.

Herwig, Nelson. 1979. Handbook of Drugs and Chemicals Used in the Treatment of Fish Diseases. Charles Thomas, Illinois. 272 pp.

Infectious diseases of fish. (translation ofSakana no Kansensho, Koseisha Koseikaku Co. Ltd, Tokyo; general editor Dr V.S. Kothekar) Shuzo Egusa A.A. Balkema, Rotterdam, The Netherlands, 1992

"Marine Head and Lateral Line Erosion: A Description of the Syndrome and a Review of its Speculated Causes". Steven Pro. Reefkeeping Magazine Reef Central. http://reefkeeping.com/issues/2005-06/sp/index.php.

Noga, Edward. 1996. Fish Disease. Diagnosis and Treatment. Mosby-Year Book, Missouri. 367 pp.


Tojo J. L. and M. T. Santamarina, 1998. Oral pharmacological treatments for parasitic diseases of rainbow trout Oncorhynchus mykiss. I. Hexamita salmonis. Dis. Aquat. Org., 33:51-56.

FAQs on Freshwater Protozoan Parasite Disease Involving Hexamita/Octomita. www.wetwebmedia.com (http://www.wetwebmedia.com)

[chc]

Great stuff there Ted.

As far as your medicated food goes, do you just use one of those gel mixes that you can buy from online fish vendors or just a grocery store gelatin?

[bobrfish]

Ted, congratulations on developing an innovative method to deliver epsom salts to site where it is needed. Again, this is wonderful account.

Unflavored grocery store gelatin will work. There are scientific grades of gelatin that are purified for experimental work. I would be surprised if this high cost gelatins are used to assist in manufacture of fish foods or pharmaceuticals.

[buntbarsch]

Ted, this is excellent information. Thank you very much for posting this here.
As you know, I am into Tropheus for the last 40 years and have killed my share. However, I have had no problems since about 20 years. I am an old fashion guy and hate to through any kind of medication and chemicals into the fish tank. When it comes to bloat, prevention is the best method to avoid this cursed disease in my experience. Your method provides all the necessary ingredients and delivers it where it is effective. I hope I will never have to use your system but should a problem develop in the future, I certainly will give it a try.

[chc]

Klaus, what is your "secret" then? I mean, 20 years with no problems? Wow!

It can't be as simple as proper food and water. For instance, are you particularly careful when you source fish?

[buntbarsch]

No secret here Chris, I just learned from the mistakes I made (and there were many).
All I do is to try to avoid anything that MAY cause stress. Sticking with a schedule is very important. I do my water changes (60%) every Saturday morning, I feed the same food at the same time every day, I never move my Tropheus around from tank to tank and I watch my fish almost every day to make sure that there is no change in behavior.
I don't buy fish by mail order. I only buy fish that I have seen in person. I have nothing against the mail order businesses but as I mentioned before, I am an old fashion kind a guy and like to see what I buy. I drive long distances if that's what it takes.
It is my opinion and experience that many South American cichlids are much more difficult to keep and breed then any of the Rift Lake Cichlids.

[chc]

Thanks Klaus. I'd prefer to get fish after seeing them in person too. With respect to tropheus, I can't find any seller that every has more than half a dozen in a tank, so if I wanted 20-30 I'd have to do something else. Thankfully there are some trustworthy sources in the ACA.

[tjudy]

Chris... I use good old Knox gelatin, but I use 1.5 packages instead of one because of the salt's effect on it. The recipe I use is actually in one of the links in those sources I listed (the one from University of FL extension).

After researching this I have become convinced that the magnesium salts are the key. I read many forum accounts and old aquarium articles that refer to the use of epsom salts; so that has been a part of our collective aquarist knowledge for a long time. However, it has only been in the past ten years or so that the scientists and veterinarians have specifically linked Hexamita to specific diseases (bloat, HITH, lateral line) and the effect of magnesium on the parasites. I now use a salt mix that is 50% epsom salts to increase the conductivity in all my rift lake tanks. Since doing so I have had no problems with bloat and the fish are breeding like mad.

[chc]

Interesting salt mix idea. Thanks Ted!

[bobrfish]

I now use a salt mix that is 50% epsom salts to increase the conductivity in all my rift lake tanks.
How many grams of magnesium sulfate per liter (or gallon) ?

[tjudy]

15g/985 ml of distilled water makes a 1.5% solution by mass. I am not that exact though, and just use 15 g/liter. I have this cool 1 liter volumetric flask I stole from school...

[bobrfish]

15g/985 ml of distilled water makes a 1.5% solution by mass. I am not that exact though, and just use 15 g/liter. I have this cool 1 liter volumetric flask I stole from school...
It was my understooding this is the concentration for preperation of magnesium in gelatin. Volumetric flasks are nifty as qs to line and avoid those density calculations. My volumetric device is a 2 liter prime bottle.

My question was not clear, what is final concentration of magnesium sulfate in tank water after adding rift lake salts?

[tjudy]

My tap conductivity is about 250 ppm (though the KH is much higher). When I do a water change use a 50/50 mix of magnesium sulfate and R/O Right (because I have a big bucket of it) to increase the conductivity back up to 800 ppm. I use a tablespoon scoop, and the rate of change in a 75 gallon tank is approximately 1 heaping scoop = 40 ppm increase in conductivity. I have a chart to tell me the approximate rates of increase in different volume tanks. Not very scientific... but it works.

[bobrfish]

Thanks Ted.