Do neutered kittens still develop an adult looking face as they grow older? I know that neutering takes away their testosterone and their ability to grow lean muscle. So.?
You can damage the lens mount, you can ding and dent the body but that part? How could you? How? If you have only one lens, glue it on. If you don't like that idea, run to the nearest Nikon Service Center right away. It would probably take some time but if its that important, you must.
The dog doesn't know it's a fire hydrant, to her it's just a pole. While some females will lift their legs to pee and some dominant dogs will mark their territory, it's not a given that all dogs will do this. Your dog will most likely go either in handy places or wherever the other neighbourhood dogs do. Edit: female dogs will mark their territory if they're dominant, and female dogs often dominate males.
Hair and nails are not lifeless. As for why we grow them beauty purposes.
Is it only one lens? Can other lenses be attached and detached? If not then there is a strong likelihood that the force required to do such damage will have caused other damage to the camera - the lens might be the only thing that is apparent. Before sending it to Canon, take into a local camera store and whether you can find a friendly staff member who can check it for you. They will probably have an idea as to whether it is a serious or simple problem.
