Peeing white stuff

Question
My friend has a mare that should be due anytime and she asked me what it means when her horse is peeing white stuff..

Answer
Hi Kaitlin,

A mare's urine PH can change during pregnancy, causing it to take on a different color.  Now, whether or not the color of the urine in your friend's mare is due to pregnancy, I cannot answer.  I do not know the actual color of her urine, so I cannot say.

White coloration, depending on the thickness also, could be a sign of some type of an infection.  This is a question that is hard to answer without seeing the actual color and without knowing whether or not there is a smell different than normal urine.