Treatments…
Most authorities recommend using the drug Metronidazole to treat this illness. It is available at pet shops under commercial names such as Hexout, Hexamit, etc. It is also available by prescription as the drug Flagyl. The dosage recommended is typically 250 mg / 10-20 gallons aquarium water. The drug is absorbed thru the gills, and works systemically. Remove carbon during treatment, maintain biological filtration. The medication is given every other day with 50 % water changes between, for a toatal of 3-5 treatments. Watch water for sign of water fouling as the medication is in a sugar base and bacteria can proliferate..
If the affected fish is still eating, it may be given in the food at a dose of gram/ 4 ounces food. This is an excellent way to treat the illness. A week of such treatment is usually required. Feed only medicated food during this time
A note on treatments…. This disease is a very common illness of fish. If you are treating it be sure to fully treat the fish . There is a very real problem with the evolution of resistence to medications. Many hobbyist have been reporting hexamita that seems resistant to the drug metronidazole. They are reporting the need to use a higher in dose to cure the ailment. This is a concern because of toxic side effects of Metronidazole at higher doses.
Among some groups of hobbyist there is also a treatment for Hexamita that uses higher water temperature. Discus and Angel fish owners report that elevating the water temperature to 92-100 degrees “cures” the disease. If your fish can tolerate that temperature it may be worth trying .
Hexamita and Hole in the Head disease. The parasite has been associated with Hole in the Head disease , and Lateral Line Erosion in some species of fish. There are even commercial medicines to treat these illness that are treating them using metronidazole. The general consensus is that these illnesses are nutritional deficiencies, and the causes for them are highly variable. Any disease state interfering with the uptake of vitamins or minerals is suspect. That includes protozoan infections like Hexamita, and infection by nematode worms such as Capillaria,. The nutritional cause may also be lack of certain vitamins (B and D -complexes – author’s guess) that are related to foods being fed, and not disease at all. In short , the illnesses are not fully characterized yet.
Personal note… Since Hexamita is so common it is highly recommended to suspect all new fish of having it, and treat new fish prophylactically in quaranteen before adding them to your tanks
Suggestions for treatment…
Treating Hexamita with Metronidazole
Dosage source of this info, “Discus Fish” by Giovanetti.
.This medication is given can be given in 2 ways:
Method 1: dissolved in a gel food at 1% by food volume = 1gram per 4 oz of food. (Most aquarium preps use capsules containing 250 mg of powdered metronidazole.) Personally, I use flake or tetra bits as the food here because it is easy to measure, and my fish readily take it. Take the food you will be using and in a small pan add some hot water until it becomes a watery paste, add the metronidazole and then add one packet of Knox gelatin(~7grams). Mix well. Using aluminum foil make a shallow 1’’ high mold and pour the food mix into this , spread it out so its about 1-2 cm thick, and let set in the refrigerator. Next cut it up into smaller squares and store in the freezer. When needed take out one of this small squares and cut it up into to bit size pieces. I use this food for until I see no signs of Hexamita (slimy white feces). Then I repeat in 2 weeks with a 3 day dose to be sure. When using metro it is recommended to do water changes between doses.
Method 2: administered at 250 mg/ 20 gallons of water (some use 250mg/10gal). It is recommended at 3 treatments , every other day, with water changes in between. The author follows this and then puts the fish on the metro food diet above until I see no sign of Hex.
Internet resources for info on Hexamita….
http://edis.ifas.ufl.edu/BODY_VM053
http://www.e-aquaria.com/ins_hexamita.html
http://www.petfish.net/unicell.htm
http://ae.inno-vet.com/articles/2000/0500/10.htm
(if anyone has this article- I’d appreciate a copy)
There are many additional sources of information on this disease, and it is generally covered in most fish disease books as well.
Hth,
al