As you know we are nearing Christmas day. My family and I are planning to have a real NOT FAKE Christmas Tree in our home. We enjoy the looks and the smell of a tree. However, I was told by a few friends that some trees contain poisionous oils to my cat. He's only 4-5 mths old. Can someone tell me if ALL trees are poisionous or only some? And if so, which ones CAN I have in my home?