Treating Hexamita aka Spironucleus with Epsom Salt Solution
This is a rather safe way to treat any newly imported fish, as a prophylactic, just as one would use a de-wormer. It's not only an extremely cheap way to treat fish, the active ingredients are readily available world-wide, and it's also much safer than using most forms of medication. Unlike most medications, there should be no worries about flagellates/pathogens building up a resistance to it, and excess magnesium is easily flushed from a fishes system. In my experience, it's very easy on fish, even very young juvenile fish. The best part - it works!
While Metronidazole has always been the drug of choice when combating internal parasites such as hexamita and/or spironucleus, metro (or any other type of medication) should never be used on a regular basis as a prophylactic, and doing so may cause flagellates/parasites to develop a resistance to the medication, and possibly even mutate and become super bugs. It's also been stated by at least one researcher that excessive use of metronidazole can cause organ damage in fish.
Other cons with metronidazole is its solubility in water is very poor, in aquarium settings it has been suggested that it can precipitate out of solution within 6-8 hours, and it can become rather expensive when treating large systems.
In fish, an excessive use of metronidazole can damage kidneys and other internal organs.(Bassleer, 1983)
While doing some online research on spironucleus I came across an interesting study that mentioned the use of Magnesium sulphate (Epsom salt) in treating internal parasites in angel fish.
A long read (200+ pages) but the idea of using something as basic as epsom salt to treat internal parasites in fish intrigued me, which in turn lead me to dig deeper.
This is where it got interesting ........
The Israeli Journal of Aquaculture Bamidgeh 57(2), 2005, 97-104.
Mortality ceased with application of medicated feed (magnesium sulfate at 3% of the feed) - Hexamita salmonis.
In his book; Fish Disease: diagnosis and treatment, Edward J. Noga mentions treating hexamita (spironucleus) orally with Magnesium sulphate.
In early June 2004, a treatment of magnesium sulfate (3% of feed for three days) lowered the parasite load to almost undetectable levels.
This is certainly encouraging news for anyone who's fish is still eating, or begins eating after treatment with Metro. Not only does Epsom salt assist in recovery when added directly to the aquarium (as per the links above), but according to the research posted above it has a deadly effect on hexamita when ingested.
Dr. Edward J. Noga, MS, DVM, is a highly respected professor of aquatic medicine and immunology, and he has been published approx. 150 times in related papers/journals. His lab at NC State University specializes in the study of infectious diseases of finfish and shellfish. As a side note for Discus keepers, Dr. Noga's book on fish disease is the book that Andrew Soh & many other top breeders often refer to for disease/treatment information.
Now for the treatment ......
For a 3% solution of Magnesium sulphate, add 1 level tablespoon (15 grams) magnesium sulphate to 500 milliliters of distilled water. Stir, and it's good to go.
Use an eye dropper or pipette to add to pellet food (or any other food that will readily absorb it), and stop dripping water once the pellets become saturated. Use only enough water to saturate the food, with no excess water, so that the water soluble vitamins in the food remain intact. Feed twice a day, for 3-5 days. (I went with 5 days)
In extreme cases, the oral solution could be administered to a fish via a pipette.Just make sure to use a flexible tip so as not to damage the fishes esophagus when squirting the solution down the fishes throat. Only a small amount is required, but repeat daily until the fish is accepting pre-soaked pellets, and continue treatment for 5 days.
My own experience with this treatment ........ so far it's proven to be a life saver, where all other previous 'textbook' methods of treatment for internal parasites have failed, including several days of treating with 500mg Metro per 10 gallons, while feeding Metro soaked food at the same time. (fish was chewing & spitting, but was eating some food twice a day)
In less than 48 hrs of the 3% Magnesium sulphate treatment, for the first time in 30 days the fish was no longer shedding the mucous lining of his intestine. (white/clear feces) After 5 days of feeding the 3% solution via pellets, the fish had made a complete recovery & was back eating like gang busters.
18 months later and this fish is still alive & doing well. Since first posting this treatment method I have heard back from numerous hobbyists that have managed to also save their fish from what appeared to be certain death.
Hopefully some members here will find this information useful.