Efficacy of medicated foods vs immersion for the treatment of internal saltwater fish parasites

[ss88]

Is the efficacy of immersion therapy as or more effective then the usage of medicated foods for the treatment of internal saltwater fish parasites?

Medications in question: Praziquantel, Levamisole, Albendazole, Metronidazole.

As we know, saltwater fish maintain osmotic balance, continuously processing saltwater through their excretory system. It's my understanding that with sufficient immersion time, whatever medication is in the water will be absorbed into the fishes system. Thus immersion should have an equal or higher efficacy?

From what I have read, medicated foods seem very difficult to administer correctly, even if you know the proper dosage amount.

 

[Jay Hemdal]

Is the efficacy of immersion therapy as or more effective then the usage of medicated foods for the treatment of internal saltwater fish parasites?

Medications in question: Praziquantel, Levamisole, Albendazole, Metronidazole.

As we know, saltwater fish maintain osmotic balance, continuously processing saltwater through their excretory system. It's my understanding that with sufficient immersion time, whatever medication is in the water will be absorbed into the fishes system. Thus immersion should have an equal or higher efficacy?

From what I have read, medicated foods seem very difficult to administer correctly, even if you know the proper dosage amount.

Good question!

For internal diseases, oral meds always excel. Of course, they are difficult to administer properly; you can’t just “mix some meds and food” like so many people will tell you to do (grin).

I don’t have the numbers handy, but I once looked up the amount of water that marine fish drink in 24 hours (at full salinity) and then calculated the amount of medication in that water for typical in-water doses of common medications - all were lower than the typical oral dose for that drug - typically about 25%. Enough to have some benefit in a pinch, but not as good as a full oral dose of the drug.
You’ve seen the med food calculator that we have here?
Jay

 

[ss88]

Jay,

Thank you for the information. Aware of the calculator, have yet to use it.

25% lower or 25% of the concentration in the water column?

In an aquarium with multiple specimens of different sizes, it would be nearly impossible to control how much medicated food each specimen consumes.

What is the protocol?

Isolate and administer medicated foods one by one? Normally fish refuse eating for a little while when tank compartment sizes change. Even if they are not directly handled. Could take a few days and many hours of work to manage a few dozen fish.

Broadcast feed and accept that some will receive double the dosage while others will receive half dosages?

 

[Jay Hemdal]

Jay,

Thank you for the information. Aware of the calculator, have yet to use it.

25% lower or 25% of the concentration in the water column?

In an aquarium with multiple specimens of different sizes, it would be nearly impossible to control how much medicated food each specimen consumes.

What is the protocol?

Isolate and administer medicated foods one by one? Normally fish refuse eating for a little while when tank compartment sizes change. Even if they are not directly handled. Could take a few days and many hours of work to manage a few dozen fish.

Broadcast feed and accept that some will receive double the dosage while others will receive half dosages?

The uptake from the treated water in 24 hours was about 25% by weight of the normal one time oral dose. So - if the proper medicated food dose was say 100 mg/day, the same medication, dosed into the water at the normal dose would result in the fish taking in about 25mg in one day.

Dosing multiple fish with oral meds is tricky, but most fish will eat about 3% of their body weight per day. Some oral meds like metronidazole, do not need to be fed by fish weight, just a simple percentage in food.

Yes - if fish aren’t eating, then tube feeding or dosing the water are the only other way to get meds into the fish.

Jay