Help - Grey tree frog in bad condition

[kueluck]

I'm taking care of the neighbors tree frogs and this is what I found. The skin coloration did not look right, and when I tried to feed it, the frog started jumping franticly and kept wiping itself like trying to remove something. This is the best pic I could get. In a few spots it looks like blood vessels under the skin are inflamed, and the back of the frog is a darker grey, around the eyes look bluish and it looks wet. That's a piece of substrate on it's back left leg. There are 3 in the tank, I took this one out to isolate it but the others don't look quite right either. Help & suggestions please. My neighbor does not return home until Saturday.