Don't Eat That Yellow Orange Snow!
I have seen this before, the discolored urine in the snow. I always thought it had something to do with the dye in the grain. Last winter after the Fjords arrived who eat bark off the oak and maple trees, I wondered if it was something in the bark. This winter horses that don't eat bark and do not receive grain, are leaving orange and reddish brown urine in the snow.
The November issue of Endurance news had an article on the color of horses urine during an endurance ride. "Red Means STOP". Ken Marcella, DVM reported a number of things that can cause discolored urine. Exercise-induced Hematuria, is when an athlete's urine is found to contain some amount of blood during or just following exercise. It listed 5 causes: Traumatic (boxing, football for people) jumping, rodeo, polo, endurance, etc for horses)
Non-traumatic: due to a reduction in kidney blood flow during intense exercise when the body redirects blood to to more urgent calls of muscle heart and lungs.
Trauma to the bladder lining from flopping around during running jumping and such.
Urethral issues (more in humans).
Horses suffering from muscle damage from sprains, strains and tears, or tying up can have myoglobinuria ( urine discolored from myoglobin released from damaged muscles and cleared through the kidneys.
I discovered that persistent red urine can mean cancer, kidney stones, bladder infection, and must be treated seriously.
I started to worry, since none of my horses where engaged in any strenuous activities. But no one appears ill in any way. I thought maybe it has to do with dehydration. I now have one horse who seems upset to drink from a hole in the ice on the stock tank and is spooked away often by the sound of ice creaking or snapping suddenly. and he is the one with the brightest shocking orange colored pee I've ever seen.
So I went out and bought and installed de-icers on two of three 100 gallon stock tanks--with help from Dan--not the banging three inches of ice from the insides of them sort of help or help lugging them onto the truck- not help with stringing together several hundred feet of extension cord and carefully wrapping yards and yards of electrical tape around the connections -but help with the technically important stuff like finding the right sort of wrench to get the large plastic treaded plug from the drain holes. (I am not complaining--after all, Dan doesn't have horses I do--and I 'm quite capable too. I could probably figure out what tool to use too if I knew how to find them. My tools have "parking spots" his are never in the same place twice)
Then I watched and waited for the urine to turn healthy and yellow once again.
Two weeks, three weeks, no change! OK back to worrying.
I posted to the forum on Eastern Competitive Trail Riding Association (ECTRA) and was told by several people that urine reacts with cold and snow and changes color to orange, pink, red brown, tea colored.
I did a web search and found more of the same. I found one source that said a protein in the urine oxidizes in the cold / snow and changes color.
But I thought protein in the urine was a bad thing (?) I guess there are different proteins. .
If anyone has more information as to what protein it is I would love for you to let me know. And why is there more in the geldings urine as his pee turns orange like cool-aid and the mares do not. Theirs is more like tea colored.
And just this Saturday I witnessed the orange pee gelding and the tea colored pee mare both in the process of peeing. Both of them produced nice yellow normal pee right to the last drop! The pee was yellow in the snow! Hhhmmm.
I cleaned the shed and puttered around and about 20 minutes later walked right over the yellow pee spot in the snow, and low and behold it had changed to bright cool-aid orange. I rushed over to see the mares pee spot. It had changed to oolong tea color! Interesting! But no more worrying!
2017 Update: found a lengthy and detailed article on this subject http://horsehints.org/UrineRedSnow.htm