Question about Praziquantel

[ss88]

Assuming specimens are newly acquired, and acclimated into a sterile system. Can praziquantel be administered once for 24hrs at 2.5ppm then the specimens be transferred to a new sterile system? Is praziquantel 100% effective at killing adult flukes that are actually attached to the fish?

Some specimens, wrasses in particular don't like praziquantel. I could see this being helpful in limiting exposure toxicity.

I have killed a few wrasses over the years using praziquantel without water changes between dosages.

Planning on acquiring a few rarer specimens in the coming months.

 

[vetteguy53081]

Assuming specimens are newly acquired, and acclimated into a sterile system. Can praziquantel be administered once for 24hrs at 2.5ppm then the specimens be transferred to a new sterile system? Is praziquantel 100% effective at killing adult flukes that are actually attached to the fish?

Some specimens, wrasses in particular don't like praziquantel. I could see this being helpful in limiting exposure toxicity.

I have killed a few wrasses over the years using praziquantel without water changes between dosages.

Planning on acquiring a few rarer specimens in the coming months.

2.5 refers to copper. For Prazi, dose at 85% of recommended and apply initial dosage known as an interval for 8 days, do a water change and do one more 8 day dose interval
Use airstone with prazi as it does reduce both oxygen and appetite. If running a skimmer, leave cup off first 24 hrs as skimmer will go nuts from the glycol solution in Prazi. 5 mL of PraziPro per 20 gallons

 

[Jay Hemdal Verified Community Expert]

Assuming specimens are newly acquired, and acclimated into a sterile system. Can praziquantel be administered once for 24hrs at 2.5ppm then the specimens be transferred to a new sterile system? Is praziquantel 100% effective at killing adult flukes that are actually attached to the fish?

Some specimens, wrasses in particular don't like praziquantel. I could see this being helpful in limiting exposure toxicity.

I have killed a few wrasses over the years using praziquantel without water changes between dosages.

Planning on acquiring a few rarer specimens in the coming months.

2.2 ppm is the standard dose for praziquantel. While your idea appears sound, in practice it doesn't work well. The reason is that prazi doesn't actually kill flukes, it just makes them relax and drop off of the fish, then they cannot get back on and then they die. However, some flukes are egg layers and have sticky eggs. The eggs are not affected by prazi and can get carried along with the fish. Just one viable egg can start the infection back up.

While my opinion is that wrasse not handling prazi well is unfounded, and when seen, is due to low dissolved oxygen, or just a coincidence, if you want to avoid prazi, you can go with hyposalinity.

Jay

 

[ss88]

@Jay Hemdal Understood, I was erroneously under the assumption, that the lifecycle of the skin and gill flukes partially occurred off of the host.

I have most recently seen a Harlequin tuskfish die with a Prozquantal treatment at 2.5ish ppm while all other 10 non wrasse specimens tolerated the treatment very well. Prior to treatment the specimen was eating and exhibiting normal behavior. Afterwards, lethargic, near complete loss of appetite, shallow breathing, pale coloration. Preformed 75% water change and no improvement occurred, death next day. Those symptoms would be indicative of poisoning, no? Antidotally there seems to be significant reports of wrasses not tolerating Prozquantal as well as other fish. While certainly not a conclusive scientific study it suggest a possible link I would think.

 

[Jay Hemdal Verified Community Expert]

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@Jay Hemdal Understood, I was erroneously under the assumption, that the lifecycle of the skin and gill flukes partially occurred off of the host.

I have most recently seen a Harlequin tuskfish die with a Prozquantal treatment at 2.5ish ppm while all other 10 non wrasse specimens tolerated the treatment very well. Prior to treatment the specimen was eating and exhibiting normal behavior. Afterwards, lethargic, near complete loss of appetite, shallow breathing, pale coloration. Preformed 75% water change and no improvement occurred, death next day. Those symptoms would be indicative of poisoning, no? Antidotally there seems to be significant reports of wrasses not tolerating Prozquantal as well as other fish. While certainly not a conclusive scientific study it suggest a possible link I would think.

Except that harlequin tusks have a very high early mortality rate if acquired from anywhere other than Australia. In 2014, I ran a group of them from Cairns Marine through prazi 3x with no issues. That same shipment contained dozens of hogfish and other wrasses - no losses at all. Again, it is a lack of oxygen that I see with wrasses, not toxicity from the praziquantel itself - but in essence, the prazi does "cause" that mortality.

Any praziquantel dissolved in a solvent is risky in regards to oxygen deprivation - ethanol, glycol and DMSO are all used as solvents, and can cause issues. I use powdered praziquantel, expressed through a fine mesh net to disperse it out into the tank.

The life cycle of skin and gill flukes DOES include eggs and oncomiracidia larvae that exist off the host. However, the point I was making is that some flukes have sticky eggs that catch up onto fish nets, or the fish themselves, and get moved along to the next tank, perpetuating the infection.

Jay

 

[ss88]

Yes im aware that this particular specimen from the Philippines has a high mortality rate. Allegedly the specimen was Australian of origin. I guess its possibly the importer lied. But the timing seems suspicious.

Yes, I do this as well. Powerhead and fine mesh pantyhose in bucket to dissolve.

I use powdered praziquantel, expressed through a fine mesh net to disperse it out into the tank.

I highly doubt its a dissolved O2 issue in this instance, skimmer is never shut off, allowed to overflow, I also run air-stones in each tank.
Low space bio filter also has excess air movement.