There are thousands of types of mushrooms. Depending on the type of mushroom, they are both healthy and toxic. Edible Mushrooms: The edible mushrooms you find in the supermarket do have various nutrients. However, organizations such as the American Kennel Club (AKC) indicate they do not necessarily need mushrooms in their diets. Mushrooms are good sources of some of the B vitamins – Thiamine (B1), Riboflavin (B2), Pantothenic acid (B3) and Vitamin B6 in particular. They are also sources of minerals such as selenium, phosphorous, copper and potassium. Toxic Mushrooms: Toxic and poisonous varieties can vary from region to region, and have different side effects. Common species of wild mushrooms in the US that are toxic to dogs include: Amanita phalloides (death cap mushroom) Amanita muscaria (fly agaric or deadly agaric) Gyromitra esculenta Gyromitra caroliniana (Big reds) Gallerina marginata (Deadly galerina) Amanita gemmata Amanita ocreata (Death angel) Amanita pantherina Clitocybe dealbata Chlorophyllum molybdites, and False morels.