Clown loaches, barbs, neon tetras - worms?

Hello Fishlore, I feel pretty incompetent and need some community help. In a nutshell (detailed sad saga below): over the past few months, a few fish died with similar symptoms that look like a worm infection. Now I see the symptoms in my favorite clown loaches and I want to save them.
Questions:

• Does it look like worms or is it something else entirely?
• Any experience with dog wormer for fish?
• What mistakes am I making?
• Anything. I am at a loss and I feel very bad about my poor scaly folks.

Tank
What is the water volume of the tank? - 350L
How long has the tank been running? - 5 months
Does it have a filter? - yes
Does it have a heater? - yes
What is the water temperature? - 25,5 C
What is the entire stocking of this tank?

1. 4 clown loaches (3 medium, 1 small)
2. 5 blue gouramis
3. 7 green tiger barbs
4. 7 corydoras
5. 2 neon tetras
6. A few ramshorn snails

Maintenance
How often do you change the water? - weekly/once every 2 weeks
How much of the water do you change? - 30% if weekly, 50% if biweekly
What do you use to treat your water? - Tetra AquaSafe
Do you vacuum the substrate or just the water? - vacuum during every water change

*Parameters - Very Important
Did you cycle your tank before adding fish? - yes, ghost feeding method
What do you use to test the water? - Sera NO3, NO2, NH4/NH3 tests, Dajana pH test kit
What are your parameters? - I check regularly, they don’t change much since the tank finished cycling.

• Ammonia: NH4 0, NH3 0
• Nitrite: <0,5 mg/l
• Nitrate: 0 - 10 mg/l
• pH: 7-7,4

Feeding
How often do you feed your fish? 2 x per day
How much do you feed your fish? Morning: 5g Hikari micro wafers + 2-3g Hirer sinking algae wafers; evening - 2g Hikari micro wafers
What brand of food do you feed your fish? Hikari, occasionally live tubifex (instead of dry food) and veggies
Do you feed frozen? Not any more
Do you feed freeze-dried foods? No

Illness & Symptoms
How long have you had this fish? - neon tetras, loaches - since August; barbs/small loaches since December
How long ago did you first notice these symptoms? Neon tetras - December; barb - February, loaches - March
In a few words, can you explain the symptoms? - fish becomes thin, looses interest in food, becomes apathetic, slightly uncoordinated, swim alone and hang near the filter intake, gills become red or stand out.
Have you started any treatment for the illness? - Esha 2000 for neon tetras, Tremazid for barbs and loaches, mixing food with crushed garlic for the past 2 days.
Was your fish physically ill or injured upon purchase? 1 of the baby loaches had malformed front fins.

Explain your emergency situation in detail.
In August, I got a tank with 4 5cm clown loaches. 3 grew pretty fast, one stopped growing and was often hanging out alone. In November, the smallest one started to swim weird and hanging out alone; then he started having seizures which looked pretty scary and painful. We euthanized him. He didn’t look skeletal, but lost weight, gills looked ok. Not sure if this one is connected.

Some time later, my neon tetras started to waste away (thin, pale, not eating, apathetic, with very red inflamed gills). LFS owner suspected neon tetra disease, and I started treating entire large tank with Esha 2000 (Ethacridini lactase 6.3 mg, cuprous 2 + 3.2 mg, Methylorange 0.26, Proflavinae 1 mg). 2 neon tetras died, 1 that was in a very bad condition recovered, one never showed symptoms.

After some time, I purchased tiger barbs and two baby loaches and put them to quarantine for 4 weeks. No symptoms showed in both tanks, so after quarantine I put new fish to the large tank. Early in February I added gouramis after similar procedure.

Mid-February, I noticed that one of the barbs was not growing and spending time alone (all others grew HUGE). He was picked by others, so I assumed it was bullying. Around March 10th, I saw him hanging near the filter intake like neon tetras did and turning almost black. I noticed that one of the large loaches and one baby loach had reddish gills on one side (like red cheeks). I read forums recollected neon tetra deaths and on March 15th I started treating against gill flukes with Tremazid (peppermint oil). The barb died on March 18th, and I noticed baby loaches being lethargic. The one with fin defects became visibly thin, got darker, and stopped feeding. It died next day after the second dose of Tremazid (March 22nd). The other baby loach looks pretty bad as well, but he is still eating. I don’t like the looks of the large loach with reddened gill: he also started spending time alone and doesn’t look as plump as the other two.

I suspect worms or in the worst case fish TB. I live in Czechia and fish medication availability is not perfect. I couldn’t find anything containing praziquantel or levamisole for fish treatment on the market. Esha Hexamita is available (ethakridin laktát 6,7 mg, Cu2+ 2,8 mg, akriflavin chlorid 2 mg, methylrosanilin chlorid 6,3 µg), but it doesn’t 100% look like hexamita. I read success stories of people using dog wormer containing praziquantel in their tanks. A few medications like that are available in the shops, and I am ready to try, but I can’t figure how to dose it for the tank.

Looking at this story, I can see I didn't react fast enough, so if you have any recommendations about the red flags and how I can react - this will be very helpful.

 

Link the dog wormers you can get.
Fenbendazole is another type of med found in dog wormers to look for also.
I have used fenbendazole22% before to kill hydra or planaria. I would guess the dose would be higher, but that is easily adjusted.

 

Link the dog wormers you can get.
Fenbendazole is another type of med found in dog wormers to look for also.
I have used fenbendazole22% before to kill hydra or planaria. I would guess the dose would be higher, but that is easily adjusted.

Hi, thanks for replying!
Dehinel plus is the praziquantel-based dog dewormer I can easily find here: https://medicines.health.europa.eu/veterinary/en/600000041300 (contains praziquantel + 2 dewormers I don't know)
I also looked for flubendazole based medications and found this from NT Labs: Aquarium Medicine - Anti-Fluke & Wormer from NT Labs I can get this one from German Amazon.

 

I would be inclined to use the aquarium med first.
Not sure what the other ingredients are in the dog med?

 

I would be inclined to use the aquarium med first.
Not sure what the other ingredients are in the dog med?

Ok, I ordered the NT Labs one and I will start with it. I found your reply in another thread where you recommended flubendazole. Sounds promising.

Dehinel (dog wormer) contains praziquantel 50mg, febantel 150 mg, and pyrantel embonate 144 mg per pill. The manual says it's efficient against ascarida (roundworms), nematodes (roundworms), and cestoda worm (tapeworms). Cant find what inactive ingredients they have, but these are the only ones that are not advertised as bacon flavored so hopefully my tank won't smell like broth

 

Note for historical purposes:
added NT Labs treatment on March, 28th; the smallest loach still looks like death, but I caught him aggressively attacking a snail that I forgot to remove before treatment. The snail is still alive although the manual says the medication will kill snails.

 

After two doses: the smallest loach died; one of the big ones that was losing weight is getting better: he is eating like crazy, swimming with the other two, and he now has a normal rounded belly. Must have been worms.

 

For the history, in case someone finds this post struggling as I did: before and after flubendazole-based treatment.

The darker photo is taken less than a week after the first dose of flubendazole. You can see red gills on one side and there is very little fat; the fish was very apathetic and spend a lot of time lying on the bottom alone.
Brighter photos are taken today, after three doses of flubendazole. The one that was sick is on the left, and his brother who never lost weight is on the right. The photo is 6 hours after feeding, so this is not a food belly, that's his normal shape now. You can still see gill redness from some angles (vertical photo), but it doesn't look as inflamed. He is active and spends a lot of time foraging with his healthier brothers (sisters? fellow-loaches).

Overall, if multiple fish are wasting away and have inflamed gills, I suggest trying some serious de-worming medication, in my case it was flubendazole based Anti-Fluke & Wormer by NT Labs. Before that, I tried two courses of Sera Tremazid (natural peppermint oil based treatment) and it didn't make any difference in my tank.

(also, so many thanks to coralbandit!)