There are many types of euc and from what I've read there are differing opinions on certain varieties not being good for gliders. I don't know enough to be able to say which these are and if it is true. That being said, anything that comes from a florist or even the euc found in the grocery stores should not be trusted.
Euc and sugar cane are something they can have and enjoy if you know that the source is safe. This link is to a very reputable euc grower, really nice folks.
http://eucproducts.com/