Horses have 3 anatomical mechanisms designed to assist in continual movement of food through the digestive tract. These mechanisms prevent the back flow of food from the stomach to the mouth, hence they cannot vomit.
1: The waves that move the food through the oesophagus (food pipe) from the mouth to the stomach move in one direction only unlike other species such as humans
2: The junction at the opening of the stomach is called the cardiac sphincter. This is a very strong band which closes after food is pushed into the stomach. This acts as a very efficient one way valve.
3: Lastly, the food pipe enters the stomach at a very steep angle so if the stomach becomes full/distended, it pushes back on this sphincter and closes it tighter.
Why are these facts important. Because horses cannot vomit, if the stomach becomes distended when the horse is unwell, normally during a colic episode, the stomach is at serious risk from rupture/popping. This is why when a horse shows signs of colic, it is very common to pass a tube to ensure the stomach isn’t over-full with gas or liquid.
During a choking episode (when food gets stuck in the food pipe), food can be seen being expelled from both nostrils along with mucous and foam. This is not vomiting.
If you believe your horse is vomiting then this is very serious and you need a vets assistance immediately!!
Don’t eat too much this weekend, we have a 2 way system