A dye can be obtained from the foliage.

HTA Guide to potentially harmful plants: 'Pets: Harmful if eaten.'

HTA Guide to Potentially Harmful Plants, 3rd Edition (2022)

In traditional medicine dog's mercury is poisonous in the fresh state, though thorough drying or heating is said to destroy the poisonous principle. The fresh juice of the whole plant is emetic, ophthalmic and purgative. It is used externally to treat women's complaints, ear and eye problems, warts and sores. A lotion made from the plant is used for antiseptic external dressings[Grieve. A Modern Herbal. Penguin 1984].

https://pfaf.org https://pfaf.org/user/Plant.aspx?LatinName=Mercurialis+perennis

Africa, Northern Africa, Algeria

Asia-Temperate, Caucasus

Asia-Temperate, Western Asia

Europe

Europe, Northern Europe, Great Britain