Always Quarantine Fish

[Unknownfuture]

As title says. I’ve had a terrible time with a large community tank. Decided to quarantined a new for 3 weeks. Needless to say it wasn’t enough time. While that fish didn’t show any signs a nemotode outbreak ensued. The crazy thing was I treated with levamisole first but as the standard dose didn’t work and the fish were flashing and showing signs of flukes so I waited awhile to treat for flukes.

It wasn’t flukes …

Needless to say the more time passed with no improvement and secondary bacterial infections started.

A last ditch attempt was the levamisole again. I double dosed the tank within ten minutes the amount of stuff shooting out the fishes backside was a spectacle. The dose was roughly 4.74 mg per litre of levamisole. They are doing much better but I have 2 more treatments to carry out.

I have a feeling I had some resistant nematodes.

I lost a lot of fish.

Please people quarantine and we wary some of these parasites have a tolerance to some medication.

 

[GaryE]

Camallanus nematodes have evolved incredibly since I first saw them. The first experience with them had them killing everything in a few days. I bought one species from a breeder, and lost them in QT. But the breeder was largely wiped out, and he had very hard to replace fish. The parasite was a new arrival in fishtanks and it killed almost too quickly to spread.
Ah, but the fishfarms gave it a crowded new hunting ground with millions of potential victims, and now, 25 years later, it feeds slowly and spreads easily. It still kills, but it isn't in a hurry.
I expect a lot of hobbyists don't read the instructions on the treatments, or don't bother following all the steps. That will give us drug resistant forms quickly enough, and it will be our own fault as a hobby.
I Qt all wild caughts 3 to 4 weeks, and all farm raised fish for 6-10 weeks. I avoid mixing the two as contact with farm fish can be fatal for wild caught fish, who encounter some very nasty pathogens if they meet up with farm stock.