NANFA-- FW: Aquaticinfo: Regarding Praziquantel

Nick Zarlinga (
Wed, 28 Jan 2004 12:50:45 -0500

>From another list. Thought it was appropriate.

Nick Zarlinga
Aquarium Biologist
Cleveland Metroparks Zoo
216.661.6500 ext 4485

><)> -----Original Message-----
><)> From:
><)> On Behalf Of
><)> dsweet
><)> Sent: Tuesday, January 27, 2004 5:29 PM
><)> To:
><)> Subject: Aquaticinfo: Regarding Praziquantel
><)> David,
><)> Regarding praziquantel. Praziquantel is effective
><)> against internal cestodes and trematodes when
><)> simply added to the water of an aquarium
><)> containing infected fish. At least from my
><)> experiences. Praziquantel added at 3.5 ppm to the
><)> water will clear red shiners of an ungodly amount
><)> of intestinal cestodes. If you treat red shiners
><)> you will never believe
><)> the size and quantity of tapeworms that can come
><)> out of an individual fish! The volume of
><)> tapeworms looks like it should exceed the volume of
><)> the fish!
><)> I have also diagnosed discus with internal
><)> cestodes by the presence of eggs and cestode
><)> segments in fecals as well as necropsy exams. A discus
><)> breeder had problems with his broodstock and
><)> wanted me to take a look at
><)> them. Praziquantel added to the water licked this
><)> problem as well.
><)> I can go on with more examples ranging from
><)> sticklebacks to sunfish. I will admit most of my
><)> experience with praziquantel is with freshwater
><)> fish. Perhaps its not as effective internally
><)> with marine fish? I find this hard to believe
><)> since marine fish would be drinking water all the
><)> time, hence actively ingesting the dissolved drug.
><)> Whereas freshwater fish are probably uptaking it
><)> through their gills or integument. Perhaps
><)> salt-water internal parasites have different
><)> percentages of calcium channels to be effected by the drug?
><)> A paper quite a few years ago in Progressive Fish
><)> Culturist (now North American Journal of
><)> Aquaculutre) also reported that encysted
><)> trematodes (it was either black grub or white grub
><)> disease) could be removed from striped bass or
><)> striped bass hybrid broodstock by adding only .25
><)> ppm praziquantel to the water!
><)> Im sure other colleagues will agree that in many,
><)> if not most cases, praziquantel simply added to
><)> the water will work wonders at removing internal
><)> encysted as well as intestinal flukes and
><)> tapeworms. I certainly would not make the
><)> statement it works on all species of fluke and
><)> tapeworms all the time. Given my choices, I
><)> prefer to add a chemical to the water rather than
><)> compound it into a diet anyday. It saves a lot
><)> of time and trouble. Especially if it works just
><)> as effectively as an injected or oral route.
><)> Doug Sweet
><)> Curator of Fishes
><)> Belle Isle Aquarium
><)> Detroit Zoological Institute
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