Which product to use for internal parasites

Hi everyone
I have guppies in my tank and have af few that are very skinny, they don't look normal to me... i dont know if i should remove them? Will the healthy and fat ones also be affected by internal parasites?

Which products/medicine can i use to cure them?

THANKS!!

 

Hi.
The best that has been recommended to me for my tanks are paraguard from seachem. But wait and check what other members say. Good luck

 

Javei,try metronidazole
8mg per liter
Remove all carbon from filter
Increase heat slowly to 29 decrease,and add extra airstone for ,ore oxygen
Keep your lights off
After 3 days do a 50% water change and redose
Personally I would remove the ones looking bad already because the chances getting them 100% again is not good and just treat rest off tank.
Sometimes it is fish TB that do that to guppies and then there is not much you can do.
Good luck