# Fenbendazole for treatment of camallanus worms - need dosage!



## Supernova

I picked up some Panacur (Fenbendazole) for treatment of my fish for camallanus worms. This specific Panacur is meant for horses, it has 100mg/mL. Not sure if that is more potent than the cat/dog formula. From what I understand I mix it in with their bloodworms but at what dosage? Any help is appreciated.

Thanks
Robyn


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## Calmer

I have not used Fenbendazole/Panacur before but this may help: http://www.petfish.net/kb/entry/154/


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## Supernova

Calmer said:


> I have not used Fenbendazole/Panacur before but this may help: http://www.petfish.net/kb/entry/154/


Thanks, I have seen that website however it talks only about the granular formula which I have read is only at a 2% potency.


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## paradigmseeker

Where did you get your Panacur from? Did it require a prescription from a vet?

I've got a camallanus worm infestation in my tank


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## bae

Let's see if I can get the arithmetic right. Everybody check me, okay, since it's too easy to be off by an order of magnitude or more.

It's a pain when they mix weights and volumes, but if we assume that the drug is about the density of water, which may not be an entirely justified assumption, it will work out. If it's a liquid, you should be just fine with this equivalence.

2% would be 2 grams per 100 grams, or 20 grams per 1000 grams.

100mg per ml would be 100 grams per liter, or (caveat about weight vs volume above) 100 grams per 1000grams, or 10 grams per 100 grams, or 10%.

By the above reasoning, the horse medicine you have is about 5 times more concentrated than the 2% granular formulation.

To help you measure, one teaspoon is about 5ml (= 5cc). That's a measuring spoon teaspoon, not the kind you eat with. The easiest way to get accurate measures when you don't have equipment to measure small quantities is to thoroughly dissolve the drug in a larger quantity of water and measure that, proportionately. E.g. if you figure you need 1/32 of a teaspoon, that's pretty hard to measure accurately, but if you mix a half teaspoon, which you can measure pretty accurately, with 15 teaspoons of water, then the dose you want will be 1 teaspoon of the resulting solution. If you make up a stock solution like this, keep it refrigerated and tightly closed and shake well before measuring the next dose.

When measuring powders or pastes, use the back of a knife or other straightedge to level the surface of the material with the edge of the measuring spoon.

For more accurate liquid measures, ask a diabetic friend for a syringe, or often a pharmacist will give or sell you a few, especially since you don't want or need a needle. Explain why you need it, and don't look like a druggie. ;-) Or ask your vet, or whereever you got the Panacur. There are also syringes that don't accept needles that should be easy to buy. They are used for measuring liquid drugs into juice or whatever to get children or animals to consume them. Some have a curved plastic spout for getting the drug into an animal's or child's mouth.

I hope this helps. And I hope some other people here with a more recent knowledge of chemistry than mine will check my reasoning and calculations!

Hm, I reread the article in the link. He's using 3cc in 100ml of water, soaking the worms, and dumping the lot into his tank -- but he doesn't say how big his tank is! It should make a difference if it's 5 or 55 gallons, after all. Perhaps he's counting on only the amount taken up by the worms and swallowed by the fish having any effect.

Your horse medicine is 5 times more concentrated than his, so if you mix 1 teaspoon of your stuff with 4 teaspoons of water, you'll have 5 teaspoons of the same concentration of drug as he does, so you can use 3cc's of this stock solution as he does. A half-teaspoon is 2.5 ml (2.5cc). A half-teaspoon per 85ml would be the same as the 3cc per 100 ml he uses.

Again, I hope this helps, and I hope I haven't screwed up the arithmetic! Let us know what happens. That bit about fish dying from intestinal impaction from masses of worms killed suddenly by Panacur is a bit alarming, so if you have a heavy infestation you might want to be cautious.


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## ameekplec.

So I looked up a few numbers in the literature for you and the numbers are all over th eplace.

There was one study involving the efficacy on eels. A dosage of 3 - 5g Fenbendazole/kg oof eel was effective at 14 days for 100% removal of parasitic worms. Unfortuntely, eels were force fed in the study.

It seems every instance that Fenbendazole is used, it is a feed additive administered orally (well there were a few studies that injected it). The lowest number I saw was using 0.25% Fenbendazole, but I assume that's pure Fenbendazole in the feed. either way, the total volume of tank doesn't seem to matter as the drug has to be ingested it seems (or delivered internally).

Since your medication is liquid, it saves a bit of trouble. You say it's 100mg Fenbendazole/ml - which is 10% Fenbendazole. I would just soak your worms (or better yet dry foods, as they will absorb more of the drug) in pure Fenbendazole. The resultant feed I'm sure will be closer to 0.25% by weight.

If you're not comfortable with using 100% drug to soak the food, try 50% drug/50% distilled water. 

Good luck


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