WebMD didn't have any advice based on the symptoms I entered, but I had better luck on WrongDiagnosis.com:
Needless to say, I'm pretty impressed with WrongDiagnosis.com and its attention to religio-mystic grammar, even though it didn't provide any treatment options.
My dog is concerned.
UPDATE: I stayed up too late last night and watched "The Endurance," a documentary about Ernest Shackleton's 1914 expedition to Antarctica. I've read so much about the golden age of exploration that I should have recognized what is happening to me as a symptom of scurvy.