More treatment options for internal parasites

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Dr. Fish
Wandering Nomad
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I never like it when only one medication is recommended to treat a particular pathogen. As most of you know, Metronidazole is the treatment of choice when a fish has Internal flagellates/parasitic diplomonads:

Some possible alternative treatments are listed in the above sticky, but I have found additional promising options below:
  1. Dimetridazole (Sold in the UK as Waterlife Octozin) / Source:
  2. Epsom salt - Magnesium sulfate / Source:
Obviously, the Magnesium sulfate option is probably the most intriguing. I've always added a pinch of it to metro soaked food when battling internal parasites. However, the first link states:
Magnesium sulfate at a concentration of >60 mg/ml inhibited the parasite growth after 72 hrs exposure.

So, maybe it's worth a shot to also dose Epsom salt (1 tablespoon per 5 gallons) whenever you see white stringy poop. No harm in trying.

P.S. Internal parasites should not be confused with intestinal worms. They are difficult to distinguish because both can cause the same white stringy feces symptom. However, intestinal worms are treated via Praziquantel; or alternatively Fenbendazole, Levamisole or Piperazine.


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Interesting. The magesium sulphate study was performed by food dosing and I think has some potential benefit for marine aquarists.

It is notable that both studies were conducted in fresh water. I still feel epsom salt has negligable impact and no theraputic value dosed into marine water.


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I mean no value as an in-water treatment. And definitely no harm in trying it.

The first link clearly shows a potential benefit as an oral treatment.