What is this stringy thing hanging off my guppy?

[St. Louis Cardinal Tetras]

Hi, I got 6 guppies for my 29 gallon tank yesterday from LFS. This morning I went to check on them and I saw one had this string looking thing hanging on him right behind is anal fin. Is this a parasite or just poop? I just lost one of the guppies. I’m testing my water parameters now. Last night I checked them before I went to bed and they were 0 ppm ammonia 0 ppm nitrites 5 ppm nitrates.

[Yanni]

It looks like camalanus worms. It's a parasite and I used levamisole to get rid of it. I got my levamisole at Select Aquatics, it's a little expensive but it really does work

[Colu]

If  it's camallanus worms by the time your seeing visible signs of parasites your fish will have a heavy parasite  burden  treat with levamisole as @Yanni suggest sometimes you will lose fish because of the internal damage the worms have all ready done 

[St. Louis Cardinal Tetras]

Thank you for your help. I spent all day trying to locate levamisole around my area to no avail. I ordered some Fritz Expel P from Amazon and its supposed to get here Wednesday. Its main ingredient is levamisole. I payed $10 for expedited shipping and all my Amazon orders have been getting here in one or two days. So I'm really hoping it gets here monday. But for the mean time I treated the tank with General Cure and aquarium salt. 

Edited April 18, 2021 by St. Louis Cardinal Tetras

[Colu]

8 minutes ago, St. Louis Cardinal Tetras said:

Thank you for your help. I spent all day trying to locate levamisole around my area to no avail. I ordered some Fritz Expel P from Amazon and its supposed to get here Wednesday. I payed $10 for expedited shipping and all my Amazon orders have been getting here in one or two days. So I'm really hoping it gets here monday. But for the mean time I treated the tank with General Cure and aquarium salt. 

General cure is not very effective against camallanus worms you will probably have to do 3 course of Fritz expel p to get rid of camallanus worms 

Edited April 18, 2021 by Colu

[St. Louis Cardinal Tetras]

I know it isn't, I just used it as a precaution to buy me some time. I was worried that they might have something else on top of the camallanus worms. I found some fenbendazole at my local farm and fleet. Im going to get that in the morning.