Ruby and I have got it down pat. A bark at the back door tells me one of two things: "I want to go outside" or "I'm ready to come back in."
But a few months ago, when Ruby – my 65-pound standard poodle -- signaled her wish to come in, the next thing I noticed was how she was holding up her left front foot, while giving me her "Do something!" look.
Standing or walking on that foot was obviously painful, but I found no wound or bite to tell me what was wrong.