Here is letter I got today from SM:
"I was in contact in the past several months with concerns about Camallanus worms in my aquarium. I have now treated with Levamisole and fenbendazole as in your article and making a food) multiple times and although improved, tonight I realized that the worm is still in my tank as evidenced by newer infected fish.
If I take all of the fish from this tank (sacrificing them) and wait, will the camallanus worms perish from lack of a host? Would I also need to take out all the shrimp (Neocaridina davidi)? If time will eliminate the worm how long would I wait until I can be sure they are all gone? (1 month, 6 months?). I really do not want to break the tank down completely as I love the plants in the tank. This tank is about 4 years old now.
I have never really had much luck with treatments. Any thoughts you might share would be appreciated. BTW, my tank is based upon your book and has a soil substrate. I have attached a picture." My Answer: Thanks for excellent feedback. I don't think there is any need to tear down the tank or kill the fish. You can expect this common parasite to pop up again and again in the future.
(A Camallanus infestation has popped up in my tanks once every decade.) Best to learn how to deal with it. Unlike other fish treatments, anti-parasite medications (Levamisole and Fenbendazole) are highly effective.
When you say "newer infected fish", I wonder if this means fish you have added to the tank since treatment. Or did you add plants, shrimp, anything from the outside. If so, they may have brought in a new infection. The solution is easy. Retreat.
However, if you have not added
anything, etc to the tank since treatment, then we have a stubborn infection of a resistant strain. This is highly unlikely but possible. I would write to
Charles Harrison or consult a fish veterinarian for advice.
Here, I'll throw in my two cents based on extensive research for my
article.
Camallunus (unlike Capillaria) don't produce long-living cysts, so if you clean fish up for a month, the tank should be good. I haven't seen an infestation since it appeared in some of my guppies two years ago.
My fish loved the Fenbendazole fish food I prepare. Shrimp love it too! Preparing it is a lot of work, so I kept feeding it to fish about every other day for many months. In fact, I have continued to prepare and feed them the stuff in order to use up my Fenbendazole powder. Also, I've been bringing in new fish, plants, etc from the outside. (I prepare a new batch of the fishfood every 6-7 months.)
I found no evidence that shrimp are hosts for Camallanus.