My fish lice saga continues

[Criscar]

So, I recently discovered there were fish lice in my pond when a juvenile fish had an absolutely enormous louse right on top of its head, and I then found another on the tail of my largest shubunkin. I cannot say with any certainty how they arrived in my pond. It could have been on purchased pond plants, or been brought in by the couple of froggy visitors who have turned up on occasion from the nearby creek, or they can even survive in a bird’s digestive tract and be spread by bird poop even from marine environments, and that creek feeds straight into a large nearby estuary full of fish and birds. So, who knows.

I researched and determined Dimlin X would be the best treatment. I have a small pond and this stuff is sold in large industrial sized quantities for $70-100, so I was very happy when my LPS offered to just give me for free the tiny amount I would need to treat my 300 gal pond (less than one tablespoon total). I treated it three times waiting 5 days in between each treatment. I did find one other full sized louse on a different fish after the first treatment but before the second treatment, and none after that.

All seemed well for a couple weeks after that until one of my fish started flashing a few days ago. Then today three fish were flashing, and I noticed a small spot on the tail of my sunrise shubunkin (of course the shyest and hardest to catch of all of them). I removed it with tweezers and placed it in my palm. In the photo it might just look like a blob, but it is definitely a very small fish louse, they are very fast and aggressive swimmers once removed from a fish, and this little thing was trying very hard to swim in the little drop of water in my hand and though you can’t see it had visible eye spots and the characteristic shape. I had a video of the ones i removed swimming in a cup, but now I can’t find it, but they are fast little buggers.

I don’t know if the fish lice in my pond are resistant to Dimlin X, or if there is an outside source reintroducing them, or perhaps if the store owner didn’t adequately shake up the large gallon container of the Dimlin-X before she gifted me some, but I‘m going to try cyromazine this time. Wish me luck!

 

[Criscar]

More flashing today so I scooped out my largest shubunkin and upon close examination she has hundreds of juvenile fish lice on her, so dosed the pond again with the Dimlin X I have on hand, even though it’s a week early for when they say you can give another dose. Just feels like an emergency situation at this point, since she can’t possibly be the only fish with this many, just the easiest to see it on against the white fins. Every one of the little brown flecks you see on her fins and operculum is a juvenile fish louse

 

[Mgessert]

How frustrating! I think the life cycle can be 30-60 days depending on the species, so you may have to treat for a while, but that product is supposed to kill all life stages I think. The Microbe Lift Lice and Anchor is available in small bottles and doesn’t break the bank. Has anyone else tried it?

 

[GBBUDD]

Repeat the treatment wait a week and retreat . or look into a salt dip

 

[Criscar]

Repeat the treatment wait a week and retreat . or look into a salt dip

I treated three times, 5 day apart each time per the instructions on the bottle at the first sign of them last month. And I now treated again a week earlier than recommended.

 

[Criscar]

How frustrating! I think the life cycle can be 30-60 days depending on the species, so you may have to treat for a while, but that product is supposed to kill all life stages I think. The Microbe Lift Lice and Anchor is available in small bottles and doesn’t break the bank. Has anyone else tried it?

I had been planning to try the Microbe Lift product (it has cyromazine) but there are so many reviews online of it being completely ineffective I ended up going for a 4th dose of the Dimlin X. Will be ordering the microbe lift also, though I haven’t been able to determine if you can use them overlapping or not.

 

[Criscar]

Same fish a few days later after the massive cluster of fish lice on her tail, a huge chunk of her tail is now just gone. The against recommendation 4th dose of Dimlin X knocked back the fish lice problem a lot but I still see a couple on her, not sure if they are dead or alive but not worth stressing her right now to find out. I’m going to hand feed her some blood worms and other goodies to help her keep her strength up.

 

[GBBUDD]

look into a salt dip i bet that will take care of your problem just beware of fish without scales they can be much more sensitive to such

 

[Criscar]

Hi, just wanted to update this thread again. The shubunkin in question died on this past Friday from either a previously ongoing disease process (she had been a bit on the slower side and a slight 2-3 degrees off vertical for several months now) exacerbated by the lice or a secondary infection from their bites.

Under the advisement of our local aquatic vet (the poor guy’s a total wreck from COVID so I hope it was good advice), I ended up dosing the pond 5 times within a month with Dimlin X, 2 additional times beyond the limit recommended on the bottle. And today, 8 days later, I pulled a live fish louse off of one of my fish. The aquatic vet thought that the heavy planting of the pond might be affecting the ability of the medicine to distribute everywhere.

 

[GBBUDD]

Potasium pergonite would be my weapon against them but it will require frequent dips.

 

[netvine]

I just picked up a bottle of the PP to clean some bio media seemed like a good price.

Potassium Permanganete Powder 2 oz https://a.co/d/ghkJruq

 

[GBBUDD]

very cheap stuff
very effective stuff
but if to strong a mix and dip the fish for to long it can kill the fish as well.
from my experiance if the fish is calm in the dip you should be ok once the fish starts twitching and moving around it's time to come out. i forget the actual dosage but pay attention to if your fish has scales or is scaless , scaless can not be dipped as long

 

[Criscar]

Potasium pergonite would be my weapon against them but it will require frequent dips.

This sounds like a good plan for any individual fish who has many small lice (only happened once to my big shubunkin who died), but that leaves the issue of how to treat the entire pond? The female fish louse lays her eggs in the plants or gravel,and the lice are free swimming and can come off and go from fish to fish and wherever, so it’s a whole pond issue, not an individual fish issue.

 

[GBBUDD]

I do not know if prazzi will work for lice but it is fantastic with fluke that are also troublesome

 

[Criscar]

So, a third fish died today. At this point I don’t know if this was a secondary infection from prior lice bites (the lice are not completely gone but the level is very low in the pond right now, I’ve only seen one in the past week) or just a slow death from last month’s vet-recommended overuse of the DimlinX. Aquatic vet is not really responsive, either Water quality is fine, bog is running fine, ammonia, nitrite are zero, nitrates nearly 0 (definitely far less than 5 on the API Master Test kit, possibly also 0). So far all the other fish seem fine. I guess I will treat with Prazipro pre-emptively just in case.