Defecation is partly dependent on diet and takes place 10-12 times in 24 hours, and is also partly subject to individual, breed-related and psychological influences. Similarly, the daily volume of urine passed depends on diet, but is also determined by fluid loss due to sweating; urination takes place 6-12 times daily. Stallions will deposit small amounts of urine over the dung and urine of mares up to 50 times a day, to mark them.

Wild horses and horses kept outdoors prefer certain sites where frequently used tracks converge or cross, to deposit their dung. Dung-piles can also provide important olfactory information about rank, the mares’ status in the reproductive cycle and membership of the herd. If horses are given limited access to pasture, they generally deposit their dung in the same places, producing areas of rank vegetation (latrine areas) (Schäfer 1993).