Re: NANFA-L-- wormy fish

Mysteryman (
Tue, 26 Apr 2005 11:52:27 -0700

Traci Greve wrote:
> I bought a few rasboras about two weeks ago, they
> seemed a little fat (in a well fed sort of way) so I
> didn't really pay any attention. After a week of
> quarantine and no signs of illness, I put them in my
> tank. They got even fatter and evidently have some
> sort of tapeworm or something in them. Now all of my
> other fish are swelling up. I thought things like this
> required an intermediate host- guess not. I found
> some information on a drug called praziquantel that
> will get rid of the tapeworms. My problem is that I
> can't find anywhere local that sells the fish version,
> prazi-pro. That leaves me with a couple of choices. I
> can go to my local vet and get the version for dogs
> called Droncit or order prazi-pro online. The droncit
> will only be financially feasible if I put the fish in
> a small quarantine tank as I would need about $60
> worth to treat the 58 gal tank they are in.
> If I take the fish out of the tank they are in, will
> the tapeworms be there when the fish get back? Would
> it be better to wait on the medicine online, or put
> the fish in a small treatment tank and not have to
> wait long?
If your fish aren't dropping like flies, then ordering Prazi-pro online
or from Foster/Smith is a perfectly viable option. Before the advent of
Prazi-pro, Droncit was commonly used and still is commonly used. It is
very pricey, but I would guess that it works better, although I haven't
made any comparisons so it's only a very wild guess. I once wanted to
use Droncit to treat Neobenedinia flukes, but the cost was too
prohibitive for such a huge tank. If Prazi-pro were available-in-the
time I certainly would have tried it.
As you surmised, no intermediate host is required for these cestodes.
Little segments of the worms are continually expelled along with the
fishes' solid waste, and these little segments are for some reason
considered edible by other fish which eat them and get likewise
infected. There are also cysts popping out of those segments to make
matters worse. Praziquantel can kill the cysts, which is why it is so
effective, and it's also very handy for flukes.
Tapeworms do not need intermediate hosts, but they still very often use
them. Tubifex worms and cyclops are common intermediate hosts for the
tapeworm larvae. The cysts need no host-in-all, and as such they won't
all just die in a tank without fish, so you'll have to treat the main
tank to avoid reinfestation.

If I were you I would order some Prazi-pro and get it shipped EXPRESS.
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