They are hard to cure and do alot of damage to fish, as they cause bacterial problems, there is one med but it hard to get hold off.
Have pemission to use this info below.
I've been derelict in my duty--I really meant to post a sticky about internal parasites long before this, and I've been so busy lately I just haven't gotten it done. Part of the problem is that I need to rewrite it, because right at the moment, levamisole is almost impossible to get, unfortunately. There is only one manufacturer producing it, and they're having financial problems and have suspended production; I sure hope it's just temporary, because levamisole is still the best, widest spectrum and most nontoxic dewormer you can use on tropical fish. IF you can get levamisole, and that's a big if right now, this is what I do:
If they’re eating, I use a ColorBits cocktail, which consists of ColorBits soaked in metronidazole and levamisole, two broad spectrum antiparasitics and antihelminthics. I get the 5 gram vials of pure metronidazole that Foster & Smith sells. It comes with a little spoon (just like the kinds that come in SeaChem water test kits). I use Tetra ColorBits because it holds together better than flakes do and it’s easy to mix. Take off the cap, put one spoonful of metronidazole and one spoonful of levamisole (available in powder from most vets, one brand name is Levasole); add about a teaspoonful of water and mix as thoroughly as you can. Add enough ColorBits to the cap to soak up all the water; mix thoroughly. One capful of this is enough for me to deworm all my tanks, which I do on a regular basis, about every 3 or 4 months; I also do any new fish I purchase while they're still in quarantine. Just feed as much as you can fit on the end of your finger. After you’ve done it a couple of times, you can easily judge how much to put in. Both of these meds are very nontoxic, but be careful if you have shrimp; you don’t want them chowing down on it. Most antiparasitic medications will kill shrimp. I’ve used the cocktail in a tank with wood shrimp with no problems, but they don't generally scavenge the bottom for food. This may sound complicated but once you’ve done it once there’s nothing to it, and the results are pretty amazing, especially when you realize fish that you thought were perfectly healthy are throwing all kinds of worms.
If they’re not eating, you can treat the water with Levamisole. It’s most effective at a ph below neutral, so if necessary you can kick up your CO2 to bring it down a little, or put a bottle on your quarantine tank if necessary. Mix ¼ teaspoon per 10 gallons in a cup or so of tank water to dissolve, and then pour into the tank. After 24 hours, do a big water change, at least 50%, and the following day do another one; this will help get rid of expelled worms and any eggs or cysts. After you’ve done two water changes, the fish should begin to eat normally and put weight back on. If it DOESN’T work, you may need to try another antihelminthic like piperazine or metronidazole or both, but levamisole is effective against a pretty wide variety of organisms, and is particularly good for everything that most commonly troubles cichlids. I have never used this treatment on shrimp and would be leery of doing so; however, it doesn’t seem to have any impact on snails.
If you CAN'T get Levamisole, one thing you could use instead is DiscoMed, a medication made by AquaTronics. It contains metronidazole, levamisole and nitrafurazone, and you can also soak their food in it and feed it that way, or treat the water if they're not eating; there are directions right on the medication. Piperazine is also a good option--it's readily available most places as Pipzine, also from AquaTronics.
They have worms hanging from their anus.
