Provided are a solution for treatment of difficult diseases in animals and plants, which has high bactericidal and therapeutic effects by extracting antibacterial substances and immune-enhancing ingredients from Reishi Kazuno； and a production method therefor. The production method for the solution for treatment increased the extraction efficiency by conducting a reduction treatment with hydrogen gas to the extracting solution and a nanobubbles process by air and oxygen gas. Long-term maintenance of functional technology of the solution for treatment was established according to an anti-oxidation treatment by reducing conditions. The effects of the solution for treatment against pathogens in plant diseases are recognized on symptom recovery by any of alcohol extract, glycerin extract, rare acid extract, rare alkaline extract, and pyroligneous acid extract. Particularly, it was found that the effects are extremely high when the period of time after the onset is short. It was found that the effects of the solution for treatment against pathogens in animal diseases recognized on recovery by any of the aforementioned extracts are extremely high when the application is conducted carefully many times as animals lick the extracts naturally, on their own.
