Sick White's Tree Frog.. Help?

[snowbuny]

I have a sick tree frog, he's 7 years old and in the last few months has gotten skinny, boney looking. He doesnt eat as much.

i have the crickets eating calcium before food time but still nada.

My other tree frog is fine, fat and eats like a pig.

any suggestions will help, see his pic below..