Diabetes affects our blood vessels and nerves and therefore can affect any part of the body. However, certain parts of our body are affected more than other parts.
I don't think dogwoods have (much?) scent, maybe just lightly floral. The white petally looking things are not actually petals they are bracts, like a poinsettia has. There's something called an English dogwood that is very fragrant, but it isn't a true dogwood and is also known as mock orange. Bradford pears have a smell that this author described as sweaty socks, so if your tree doesn't smell very good that's probably it: http://www.gardenguides.com/106133-dogw ...
Nearly all dogs dislike the smell of citrus, whether it's oranges, lemons, limes or grapefruit. Fortunately, most people enjoy the fresh smell of citrus and it's not dangerous or harmful, making it handy for use around the house and yard. Fresh citrus peels make a great temporary repellant. Mix concentrated lemon juice with water for a repellent spray that is safe to use almost anywhere.