Dandelion leaves are not poisonous for cats. In fact, they are considered to be a healthy food for cats. Dandelion leaves are a good source of vitamins A, C, and K, as well as minerals such as calcium, potassium, and iron. They are also a good source of fiber, which can help to keep your cat's digestive system healthy. Some people believe that dandelion leaves can help to improve liver and kidney function in cats, but there is no scientific evidence to support this claim.
If you have a cat, you can give it fresh dandelion leaves as a treat. However, be sure to wash the leaves thoroughly before feeding them to your cat, as they can sometimes be contaminated with pesticides or herbicides. You can also give your cat dandelion supplements, which are available at most pet stores.