Now that is true, and I don't deny that uninfected fish sometimes seem a bit subdued. Or that the necessary dose is about half the fish LC50 I saw in one research paper. This worried me enough that my first treatment attempt was half what Charles recommended. It didn't work.
Though I haven't seen any snail deaths, or recall seeing anyone else report this. Did this happen for you? If not, are you possibly confusing Levamisole with Flubendazole, which is a guaranteed snail killer?
It worries me too. A lot. Callamanus is only becoming such an issue now because it's developed resistance to most common anthelmintics. If it develops improved resistance to Levamisole too, we're in trouble.
ya... i lost all of my snails... This is all if could have been.
The fact that lev is hard to obtain is what is worrysome