Toxic plants can be found everywhere in nature, including horse pastures. In recent years, particularly due to climate change creating more favorable conditions, extremely toxic plants for horses, such as ragwort, have spread significantly. Unfortunately, the instinct of our domesticated horses is no longer as reliable in preventing them from consuming harmful plants as it is in their wild relatives. This book provides an overview of the most important toxic plants, organized by their most distinctive features, such as flower color and the number of petals, allowing even botanical novices to quickly and accurately identify them. An additional list of toxic fruits facilitates identification outside of the flowering season. For each toxic plant, the appearance, occurrence, and other relevant information are provided.