Having been around racoons and their latrines for a long time, I wonder why you think it's red? Of course, an animal can eat certain substances or even have a disease that can cause an abnormality, but I've not encountered this....
My guess is that it's red at certain times of the year only, and this may be because they have eaten the berries of the yew tree, yew has a purging action and I think this is natures way for the raccoons the cleans their stomochs, I noticed fox's do this around this time of the year too.