I have never heard of that happening around here but then again we do not have long periods of snow on the ground and do not see the color of the urine that often. I would be interested to know what was causing the blue.

Maybe it was leaving a trail so it knew how to get home?

I've seen it several times this year. I assumed it was from eating red cedar branches(green) and juniper berries (which are blue), the main food scources where the deer were. This was particularly true here in the northeast, shere the snow cover has been several feet thick for the past month,and no ather food scources were readily apparent.

Papa Smurf...................

That's a good point, Buckstopshere. I've got to think that it has something to do with the available food, as you've stated.