I have some questions:

1. What type of toad is he?
2. Can you slightly mimic his natural habitat? (it helps reduce stress)
3. How much has he eaten?
4. Does he look thin?
5. Have you tried letting him not eat to the point of starvation, when this happens they usually begin eating. or did you immediatley try feeding him and he has only gone maybe a month without food?

Toads can go a long while without food. As long as he isnt sickly, he should be fine. They dont usually starve themselves to death and will actually eat whatever they can.