Red Eyed Tree Frog - Not eating\defecating

[Pembina]

I've got a 1-2yr old Red Eye Tree frog that has not been thriving as of late. He doesn't eat very much, and has maybe defecated 4 times in the past 6 months. He is very slowly getting wrinkly and seems to be loosing weight. His water dish is always very clean, temp. and humidity are perfect. Any ideas as to what is going on?