system
Given the following post, respond as if you're commenting on Reddit:
human
[MGSV: Phantom Pain] What are they feeding poor D. Horse to cause his poop to be slippery enough for cars to skid out of control?

So, in MGSV you can make D. Horse poop on command if you get his loyalty up enough. I could understand infantry and Walker Gear possibly slipping on it, but i have hard time believing that normal horse poop would be slippery enough to do it for cars...
gpt
Its the stress, not the feed. He is constantly being ridden in firefights, transported via crazy ballons, run over, and otherwise terrified or injured, all while running around stopping biological weapons and all kinds of parasites. Horses tend to react poorly to all that, and intestinal issues are common in high stress horses.