section_path: Biology/Anatomy/Digestion
section_name: Digestion
paragraph_text: Digestion
  
  Horses are herbivores with a digestive system adapted to a forage diet of grasses and other plant material, consumed steadily throughout the day. Therefore, compared to humans, they have a relatively small stomach but very long intestines to facilitate a steady flow of nutrients. A 450-kilogram (990 lb) horse will eat 7 to 11 kilograms (15 to 24 lb) of food per day and, under normal use, drink 38 to 45 litres (8.4 to 9.9 imp gal; 10 to 12 US gal) of water. Horses are not ruminants, having only one stomach, like humans. But unlike humans, they can digest cellulose, a major component of grass, through the process of hindgut fermentation. Cellulose fermentation by symbiotic bacteria and other microbes occurs in the cecum and the large intestine. Horses cannot vomit, so digestion problems can quickly cause colic, a leading cause of death. Although horses do not have a gallbladder, they tolerate high amounts of fat in their diet.