There are plenty of things it could have been, grindel worms and nemerates come to mind. Grindle worms will come from the environement and nemerates come from inside the frog, but arn't that harmful. The only way to tell for sure it to get fecals done. I would get them done from dr. frye. http://fryebrothersfrogs.com.
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A room of herps.
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