Dealing with prazi resistant flukes?

[Humblefish]

It's going to happen sooner or later... You treat with Prazipro (or General Cure), wait 5-7 days, do your 25% water change and dose again. And yet flukes remain on the fish.  🙄

 

One important step you should take when determining when is the best time to administer the second dose is use this treatment calendar: http://www.marineparasites.com/paratreatmentcal.html

 

It takes water temperature & salinity into consideration, and provides a more accurate dosing schedule than the generic "5-7 days."

 

But what if you still have flukes despite following the treatment calendar? Well, if you used API General Cure give Prazipro a try next before moving on to other options. The reason is because General Cure only contains a praziquantel concentration of 2.0 mg/L vs. Prazipro's 2.5 mg/L. To be clear, 2.0 mg/L prazi is considered therapeutic; however Prazipro's "overdosed" 2.5 mg/L concentration is obviously going to be more effective. (If you keep having problems with flukes getting through General Cure, I recommend shaking or rolling the canister to be sure the prazi/metro powder ratio is more evenly distributed.)

 

What if even Prazipro doesn't get the job done?? Below is a list of alternative treatments for flukes, in order of preference:

• Fenbendazole: 12 hour bath treatment at 25 mg/L (95 mg/gallon). It would be advisable to transfer the fish into a sterile QT following the bath treatment (to prevent reinfection), and to perform a second bath + transfer 1 week later to eliminate any hatchlings.
• Hyposalinity for 1 week eliminates both juvenile & adult flukes, and prevents egg hatching.
• Formalin: 45 minute bath treatment at 0.6 ml per gallon, or 12 drops per gallon. It would be advisable to transfer the fish into a sterile QT following the bath treatment (to prevent reinfection), and to perform a second bath + transfer 1 week later to eliminate any hatchlings.
• Hydrogen Peroxide (still experimental): 75ppm H2O2 for 30 minutes. To achieve this concentration, dose 0.625 ml of 3% H2O2 per 1 cup of saltwater OR 2.5 ml of 3% H2O2 per 1 liter of saltwater. It would be advisable to transfer the fish into a sterile QT following the bath treatment (to prevent reinfection), and to perform a second bath + transfer 1 week later to eliminate any hatchlings.

The reason I prefer Fenbendazole is because I have yet to see any flukes get through that. It is a PITA to do a 12 hour bath treatment, but Fenbendazole is probably one of the safest medications to use on wrasses and other "prazi sensitive" species. 

[mcarroll]

Can you give any insights on identifying common flatworms under a scope?   I don't have the quote, but at least one reference (Noga) says treatments can be very specific in some cases.....so that could help!

 

There are probably some exceptions, but a freshwater dip should still be a widely effective option to give fish immediate relief from flatworms.

[Humblefish]

12 hours ago, mcarroll said:

Can you give any insights on identifying common flatworms under a scope?   I don't have the quote, but at least one reference (Noga) says treatments can be very specific in some cases.....so that could help!

 

There are probably some exceptions, but a freshwater dip should still be a widely effective option to give fish immediate relief from flatworms.

I don't have wet mounts, but only three families of Monogeneans infect saltwater fish:

 

1. Ancyrocephaladae – common to freshwater, brackish and marine fish. They have 14 hooks which insert into the fish’s skin to maintain contact. They are oviviparous (egg layer). They are not host specific and they prefer the fish’s gills and esophagus.
2. Gyrodactylidae – common in freshwater but can be found on saltwater fish. They have 16 hooks and are viviparous (live bearing). This family of flukes is considered “Russian dolls” meaning that a live daughter is inside the mother and the live daughter can also be carrying a live daughter.
3. Capsalidae – common in saltwater fish. They have 2 hooks and are oviviparous. The most common genus of Capsalid found in saltwater aquaria is the Neobenedenia. It is host specific, attacking angelfish, butterflyfish, and elasmobranchs, to name a few targets and location specific (face, lips, and eyes). However, if a fish has an extensive infestation the fluke will find somewhere else on the body to host.

 

Of the above, Gyrodactylidae seems most prazi resistant IME. A 5 min FW dip is very effective against "skin flukes", but less effective on gill flukes. Also, I've witnessed flukes "hiding" under a fish's scales to seemingly shield itself from freshwater and chemical treatment. They ain't dumb. 😉 

[mcarroll]

That's great info!

 

I've had to use a net to dislodge individual flatworms before, prolly since they were "dug in" between the scales.   Seemed to be mostly around the eyes or under the fins near the body where the scales get very small.

 

But since freshwater turns these flatworms to an almost sheet-white from virtually invisible, even the tough ones are at least easy to target while the fish is in the freshwater dip.

 

It's definitely not a bad idea to dip the target fish more than once if it seem necessary...I've dipped fish two or maybe even three times a day if it seemed called for, but that was very unusual. 

 

Catching a fish is always stressful to the fish but a freshwater dip is one of the least-stressful "treatments" we can do and always seems to visibly bring relief to the fish if there was a specific reason for dipping them.  Some fish seem to get so relaxed in the dip they seem to doze off to sleep. 

 

I'm anthropomorphizing more than likely (maybe not), but I get the vibe that it really is sleep or dozing when that happens and that it's from the combination of relief from the dip plus exhaustion from the ordeal the fish have usually been through up to that point.

 

Anyway, a freshwater dip is low-stress and 90% of the time one dip does it IME with flatworms....with no further "targeting" required.

 

BTW, did you happen to notice AmScope has a basic 1000x "kids scope" on their back to school sale for just over $50?  Even comes with some pre-made slides and some blanks to make your own!

100% metal, full size scope, full size optics, slanted viewer....that's no kids scope!  😉 

 

OMAX and other scope makers seem to have similar deals.

 

(More people who keep reefs need to have and use a microscope!  Self included.  Threads like this are encouraging!)

 

34 minutes ago, Humblefish said:

I don't have wet mounts,

Does that mean "permanent" slides?

 

For "everyday" use (temporary usage), what do you think of using "concave slides" that have a small well vs being totally flat, along with using a coverslip?

 

I have flat slides and concave slides and haven't been able to use them enough yet to tell if one's any better for our purposes than the other.   (Flats are way cheaper...no contest on that front.  Just wondering about function.)