Is perlite toxic to red eyed tree frogs?

[deranged chipmunk]

If there are fertilizers in the substrate, then yes, it would be toxic. Perlite if accidentally ingested can cause an intestinal obstruction.

i tend to disagree a bit here Heather. it really depends on the fertilizer. something like worm castings or bat guano (or i could name more..LOL) are all natural and have chemical compounds in them that the frogs frequently encounter on a daily basis in the wild. but those fertz they put in stuff like Miracle gro, i would agree, very toxic. but not from the actual chemical compound of the fert, it's the binding agents they use that are severely toxic to animals.