Camallanus worms, need very specific help


Feeder Fish
MFK Member
Oct 8, 2020
Hope your treatment goes well. Mine went by already, I lost about a quarter of my fishroom (only had about 90 fish at the time, lost 20 something) but the populations that could, recovered. Thing that got hit the hardest was my guppy colony, my rams and a male convict died of secondary infections, and I lost a redeye tetra that couldn't handle the treatment. I also lost the ricefish that brought it into the fishroom in the first place of course. I did a single week's worth of levamisole treatment and 3 weeks of fenbendazole.
So sorry to hear that. Camallanus are a truly awful living thing. It broke my heart when the killifish I got from the petstore died of it... she became so very pale and weak after weeks of trying to treat her with increasing doses of fenbendazole (since levamisole isn't approved for vet use in canada it was the only worm prescription I could get within a week) and she had always had such a peaceful and calm personality for her species.

I really hope that doesn't happen to my killifish, I love those little guys so much, raised them from eggs and I only have 2 that haven't been in the contaminated tank.... On the plus side one of the males reached breeding age I guess and suddenly started mating with one of the females when I let him back in the tank after a while (not even quarantine was working to prevent the spread and it was stressing all the males out so I gave up on that), so I might at least have a worm-free next generation if I can't cure these guys..... and I've not seen any confirmed cases with my peacock gudgeons, so I'm wondering if they're somehow immune or something? I never see them poop and I can't even tell where their anuses are tbh lol so who knows.. I also have reason to believe otocinclus might not be susceptible to it either due to their weird spiral digestive system and because they don't try to eat any random particles in the water. Wish I knew more about what species it affected I guess

Well, based on posts I've seen of people's experiences with these worms, there's a chance that camallanus doesn't infect fish as easily outside of the Ovalentaria clade? Ovalentaria includes guppies/livebearers, killifish (ricefish are a type of killifish too), cichlids, blennies, rainbowfish, halfbeaks, toothcarps, mullets, leaffishes, damselfishes, and more. The majority of reports I've seen on these parasites have been within this clade, and the only others outside of that were tetras. This might just be an assumption though since theyre all the most common fish people keep, but it's interesting that 5+ of my killies have come down with adult worms, but none of the other species have from what I've seen....


Feeder Fish
MFK Member
Oct 27, 2021
I can recommend you this way to get rid of worms. You can use Anthelmintics such as fenbendazole. The drug is either administered orally with food (0.25% content) or applied in long baths. It is better to buy pure fenbendazole capsules without extra impurities.
Also, adhere to these recommendations: Do not use paddle crustaceans collected in water bodies where fish live as live food. If infected fish accidentally get into the aquarium, you should keep good aquarium maintenance. Removing excrement and fish remains will help limit the spread of parasites.


Feeder Fish
MFK Member
Jun 28, 2021
I do believe Levamisole HCL can fix roundworm infestations, and Camallanus is a roundworm.
Dose 3mg/L for 4 treatments, in one week intervals. Do WC at 75-90% before each treatment.