Praziquantel Treatment

[Jay Hemdal]

Why do you treat with 3 consecutive Prazi treatments in your QT protocol? I would think the 3rd treatment is pretty darn near useless also...

That is done specially to kill young flukes that hatch from eggs. You need to break the life cycle. Prazi doesn’t harm the eggs, it just causes the adult flukes to become catatonic and drop off the fish. If you just dose once, any eggs in the tank then hatch out and the fish get reinfected. The third dose is needed because the timing of when the eggs will hatch isn’t precisely known. By that point, the lifespan of prazi is pretty darn short. Many times, I’ve had it fail to break the life cycle of Neobenedenia…so I prefer to use hyposalinity in that instance.
Some flukes are livebearers, so one good prazi dose will take care of them….trouble is, you may not know what species you are treating, so worst case scenario is that they are egg layers, do you need multiple treatments.

Jay

 

[adittam]

That is done specially to kill young flukes that hatch from eggs. You need to break the life cycle. Prazi doesn’t harm the eggs, it just causes the adult flukes to become catatonic and drop off the fish. If you just dose once, any eggs in the tank then hatch out and the fish get reinfected. The third dose is needed because the timing of when the eggs will hatch isn’t precisely known. By that point, the lifespan of prazi is pretty darn short. Many times, I’ve had it fail to break the life cycle of Neobenedenia…so I prefer to use hyposalinity in that instance.
Some flukes are livebearers, so one good prazi dose will take care of them….trouble is, you may not know what species you are treating, so worst case scenario is that they are egg layers, do you need multiple treatments.

Jay

Ah, that makes sense. I wonder if it'd be possible to transfer the fish from the QT treatment tank to a separate sterile QT tank a certain number of days after the 2nd prazi treatment (or even after the 1st prazi treatment?) to shorten the time needed for a standard QT protocol?

 

[Jay Hemdal]

Ah, that makes sense. I wonder if it'd be possible to transfer the fish from the QT treatment tank to a separate sterile QT tank a certain number of days after the 2nd prazi treatment (or even after the 1st prazi treatment?) to shorten the time needed for a standard QT protocol?

Yes, that can help. However, Neobenedenia eggs have sticky tendrils and often get pulled along when you move the fish. I’m not sure about other fluke eggs.
Jay

 

[DrZoidburg]

From what I under stand they did find some in water samples very low levels. Those phragmites got it from the water. Also too bad they did not mention how far away from farm it was. Figuring it was degraded along the way at least a little but metabolized to other quinoline type ring structures. Which could account for many types of the metabolites found. Very much how some amino acids are metabolized by bacteria to other amino acids. Truth of the matter it is hard to find nor many researches that provide solid info on this. I would be willing to bet that there is more than just common waste products.

 

[adittam]

Yes, that can help. However, Neobenedenia eggs have sticky tendrils and often get pulled along when you move the fish. I’m not sure about other fluke eggs.
Jay

Cool, thanks Jay!

I’ve got an idea about a modification to your QT protocol to make it quicker…what are your thoughts?

Days 1 – 3: Observation - let the fish settle in and determine proper diet.
Day 4: Begin Copper Treatment
Days 5 – 34: Continue Copper Treatment
Day 35: Copper Done
Day 36: Praziquantel Treatment #1
Day 41: Praziquantel Treatment #2
Day 44: Remove fish from QT treatment tank containing Praziquantel and perform 5-minute freshwater dip. After FW dip, place fish in sterile QT tank and begin 10-day copper treatment.
Day 54: QT complete.

Or...

Day 44: Remove fish from QT treatment tank containing Praziquantel and perform 5-minute freshwater dip. After FW dip, IF AND ONLY IF the fish has shown no signs of disease throughout the QT process: QT complete, transfer fish to DT.

 

[Jay Hemdal]

Cool, thanks Jay!

I’ve got an idea about a modification to your QT protocol to make it quicker…what are your thoughts?

Days 1 – 3: Observation - let the fish settle in and determine proper diet.
Day 4: Begin Copper Treatment
Days 5 – 34: Continue Copper Treatment
Day 35: Copper Done
Day 36: Praziquantel Treatment #1
Day 41: Praziquantel Treatment #2
Day 44: Remove fish from QT treatment tank containing Praziquantel and perform 5-minute freshwater dip. After FW dip, place fish in sterile QT tank and begin 10-day copper treatment.
Day 54: QT complete.

Or...

Day 44: Remove fish from QT treatment tank containing Praziquantel and perform 5-minute freshwater dip. After FW dip, IF AND ONLY IF the fish has shown no signs of disease throughout the QT process: QT complete, transfer fish to DT.

Sure - there is lots of different ways to quarantine. As long as the time isn’t cut down to much, or ineffective treatments are used, they will work. There is NO 100% effective method.
one comment; I’m not a fan of relying on FW dips as a treatment, if parasites are present, rarely are they completed removed by the dip. I prefer to se dips to quickly reduce parasite loads in preparation of another treatment, or as a diagnostic tool to screen fish for flukes.
Jay

 

[adittam]

Sure - there is lots of different ways to quarantine. As long as the time isn’t cut down to much, or ineffective treatments are used, they will work. There is NO 100% effective method.
one comment; I’m not a fan of relying on FW dips as a treatment, if parasites are present, rarely are they completed removed by the dip. I prefer to se dips to quickly reduce parasite loads in preparation of another treatment, or as a diagnostic tool to screen fish for flukes.
Jay

So, I guess my thought with the freshwater dip was that it would be both a diagnostic tool that would indicate if a longer QT is needed, and a treatment tool to detach any sticky eggs that had made it through the previous ~10 days of back to back prazi treatments. Not useful enough to ditch the 3rd prazi treatment (if no flukes are seen in the FW dip), in your opinion?

 

[Jay Hemdal]

So, I guess my thought with the freshwater dip was that it would be both a diagnostic tool that would indicate if a longer QT is needed, and a treatment tool to detach any sticky eggs that had made it through the previous ~10 days of back to back prazi treatments. Not useful enough to ditch the 3rd prazi treatment (if no flukes are seen in the FW dip), in your opinion?

No, not in my opinion, but that's based on not having actually tried it....your mileage may very (grin).

Jay