Cats are often very similar to humans but treats that are tasty to us can be dangerous to them. Some common human foods that are poisonous to cats include chocolate, grapes, raisins, onions, garlic, and spices like cinnamon, oregano, and paprika. These foods contain compounds known as cyanogenic glycosides which are toxic to cats when eaten in large quantities. If your feline eats these foods in small quantities over time, it can build up in their system and cause serious health issues such as vomiting, diarrhea, or even kidney failure. Household plants also have the potential to be toxic if ingested by a cat. For example; lilies have a high amount of oxalic acid which is poisonous to cats and can cause them acute kidney failure if they eat large amounts of it. There are also other poisonous plants that are commonly found outdoors, such as holly and ivy, and you should be careful with them as they contain saponins which can be harmful to animals.