Guppy fry with parasites?

[Karen B.]

Greetings 

Last week I bought 6 adults guppy and a surprise fry. One of the adult guppy was always pooping long white strings, despite me feeding then food soaked in garlic. Eventually its tummy sank in, its fins got stuck together and he died.

My fry is also always pooping long white strings. He is growing and, apart from yesterday where he spent half the day laying on the substrate, he is active and eats, etc. 
My other guppies (the joy if buying in big fish stores....sighs) keeps rubbing on decor so I suspect gill flukes so I am treating them with salt. Will it help the fry too? Is he constipated or is it parasites? Anything else I can do? (Keep in mind, no meds, am in Canada)

[Ken Dyer]

The symptoms sound like internal parasites for the male, especially the slowly getting skinny leading to death. Can you get dog dewormer at a local pet store? A lot of dog dewormers also have praziquentenal as a main ingredient and you may be able to use one of them and math out the dosage.

I have only used salt for bacterial, fungal, and ich so not sure how effective it is for internal worms.