Imam Ahmed said, “(Killing) frogs is not allowed for medicinal purposes, because the Messenger of Allah has disallowed killing them. “Ahmed was referring to the Hadith that he narrated in his Musnad in which Uthman bin Abdur Rahman said that a doctor mentioned using frogs for medicinal purposes, and the Messenger disallowed killing them.
The author of Al-Qanoon said, “Eating the meat or the blood of the frog might cause swellings in the body, pale color and [uncontrollable] ejaculation until death. This is why the doctors hesitate to use it for medicinal purpose because of its harm.” There are two types of frogs, land and water frogs. Some of the land frogs are POISONED.