Is nystatin drop safe for gold fishes?!?

Question

Hi, I have been keeping a gold fish for 2 years.About 1 week ago, a black halo has appeared around its mouth and distal of its fins & tail,which is progressing proximally, destructing its beautiful long tail! :(
Actually I have bought him from a merchant by the street and he got sick in the beginning , but I gave him some tetracycline powder & he recovered! Actually I'm a medical student and I think its current illness resembles fungal diseases, but now I love him so much that I can't just try another human drug by chance and without consultations, pleeeeease help me... is nystatin safe?! and do you think it's all my fault eradicating its normal flora by that tetracyclin?! :(

Answer 1

Contrary to another answerer, there is no difference in human drugs and fish drugs. Tetracycline is tetracycline whether you give it to man, a monkey, or a catfish.. It is the first drug of choice for a bacterial infection, with E'mycin running a close 2nd. These are sold as Maracin and Maracin II in fish shops and can get rather expensive, When I was in retail and wholesale, I bought my drugs I used in the fish tanks through a local druggist with a script from a doctor. I bought in lots of 100, 500, and even 1,000, and it was so much cheaper, some generics costing hardly more than a penny each. I've used a lot of treatments in 40 years, but nystatin is not one of them so I don't know what it would do.

Your description doesn't necessarily sound like a fungal infection, but more bacterial. I'd take that approach first, as it is more urgent. Go the tetracycline route again, at 250 mg/10 gallons. with a 50% water change and a repeat treatment in 3 days. Then after a week. do 25% changes for several weekd until all the med is gone. If you aren'y using it, go ahead and add a cup of ice cream salt per 10 gallons and then proportinally when doing water changes.

I'd go this way first and if no improvements are noticed in 3 days, let reassess the situation. I'll be glad yo help if I can.

Answer 2

I've treated a number of fish, both in pet stores and at a University where I worked (see my profile), and what you're describing sounds as if it's a combination of causes.

When a goldfish turns black, it's usually caused by a chemical irritant (something like a chemical burn on its skin). My thoughts on this are that when you used the tetracycline for the previous illness, you destroyed the beneficial bacteria that convert the harmful nitrogenous wastes from your fish (ammonia and nitrite) to nitrate, and it's a high exposure of annomia that's the cause. Ammonia and nitrite can both be fatal on concentrations of 1 ppm, and lower exposure can be fatal with a long enough exposure time. You can get a test kit, or have your pet store test your water to confirm this. All that's needed is to do more frequent water changes (or change a slightly larger water volume with each change) to keep the levels within a range tolerable to your fish until the normal bacteria has a chance to re-establish.

If nitrite is a part of this, adding a small amount of non-iodized salt (1 tablespoon per 5 gallons of water volume) will help reduce the effects of the nitrite on your fish.

The fin damage as you describe could be bacterial fin rot, if the fins actually flake off in pieces from their outer edges. Sometimes a secondary fungal infection can occur as well once the initial damage is done. This can be treated by using antibiotics, but you'll be disrupting the bacteria again, so be prepared for this. Fin damage can also occur as a result of higher ammonia concentrations, and this involves splitting of the fins from the outer edge inward.

At the very least, I'd suggest stepping up your tank maintenance to give the best possible water quality. Depending on the cause of the fin deterioration, this may be enough to bring your fish back to health. If you suspect bacterial fin rot from the nature of the fin deterioration, I'd go back to tetracycline or try one of the other antibiotics listed in the link I'll post below. These have a longer history of use with fish, so there's no worry about dosages or safety.

It may take a few weeks for the black markings to go away completely.


ADDITION: Here's a link which may help you to diagnose the fin problem and proper treatment correctly: http://www.fishyfarmacy.com/fish_diseases/fins.html If the cause is indeed bacterial, you should first find out if the cause is gram positive or negative (and in a nursing program, you should have the resources to do this) before committing to a treatment, or using a broad-spectrum antibiotic (Furanase) which would cover both possibilities. Both tetracycline and erythromycin have declined in their popularity as medications - partly because so many bacteria are now resistant to these - so even if you do use them, it's not a guarantee that it will clear up your problem. If you don't see success, try Kanamycin or Nitrofurazone. As mentioned in the fishyfarmacy link, you might also want to test your pH and hardness (which in turn can affect the pH). If you have any carbonate material in the tank (shells or coral as decorations or limestone/carbonate rocks), or naturally high pH water, this can lead to fin problems. You can test any items in the tank with a few drops of vinegar (outside the tank, of course) and if anything fizzes (reaction of acid with the carbonate), it should be removed from the tank.


ADDITION 2: Non-iodized salt is fine to add for parasite or fungal infections, or in the case that your fish might be suffering from nitrite poisoning. But the suggested dose is a tablespoon per 5 gallons to a tablespoon per gallon. If added at the rate suggested by another answer (1 cup per 10 gallons) you're adding far more than needed. A cup equals 16 tablespoons, and at this amount, the salt acts as an irritant itself. This level might be acceptable for a dip of 5 minutes or so, but is higher than the fish should be in for any length of time, and is beyond any theraputic levels. If you'd like some info on salt from an independent source, see this link: http://www.skepticalaquarist.com/docs/health/salt.shtml

Answer 3

you'd get a lot more answers if you weren't trying to show off your big words, many of which don't make sense together but I got the gist of what you meant...

anyway, there are plenty of fish medications out there, no need to use human meds. a lot of people like jungle fungus eliminator but there are lots of brands out there.