These toads will "puff-up" before shedding. If there isn't any other signs, like skin discoloration, lack of appetite, abnormal behavior or poor swimming ability, then your toad is probably OK. However, taking your toad to the vet will be necessary if symptoms get worse. Abnormal bloating, sometimes called edema, is caused by poor husbandry and simple changes in water chemistry maybe all that is necessary. Always make sure that the water is properly conditioned and at the right temperature. Since these toads love water and sometimes secrete a toxic substance, make sure you make frequent water changes. Good luck!