Intubation (tubing) is the insertion of a tube into a bodily orifice to add or remove fluids or air. The passage of a nasogastric tube into a horse’s stomach has great value, both as a diagnostic and for providing treatments. It is used therapeutically to release painful gas and fluid built up in the stomach and to stimulate the gastrocolic reflex.

A vet passes the tube through a nostril into and through a specific nasal passage, and into the pharynx, where a swallow is encouraged. The tube is then fed into and down the esophagus 3-4 feet to the tight band of muscle at the entry to the stomach. This band is gently pushed open and the stomach is entered.

Like many other aspects of equine veterinary practice, the proper use of a nasogastric tube is an art that takes years to develop. The skill itself is not difficult, but the value lies in being able to discern subtle differences that help narrow a diagnosis and determine a course of treatment. In addition, good horsemanship helps teach a reticent horse to accept this procedure. Generally, a twitch is not necessary, but sometimes it can help.

Upon entry into the stomach if excessive gas buildup, intestinal fluid or feed comes back into the tube this may indicate that the horse is suffering from a blockage (obstruction) within the small intestinal or stomach.

Tubing is sometimes used to deposit water, mineral oil or electrolytes into the stomach. Filling the stomach with fluid encourages movement (motility) of the colon and other downstream regions, stimulating those areas to regain function. Primary indicators of efficacy are the lessening signs of abdominal pain, lower heart rate, and better mucous membrane color, and increased gut motility.

I use my mouth on the tube to siphon fluid and gas from the stomach, and to inflate the esophagus to open it as I pass the tube down. While this technique may seem gross, I have found it a very effective way to locate and siphon fluid. There is the potential to be infected by organisms (like Salmonella) growing in the horse's intestine. I have been in practice 20 years, have "tubed" thousands of horses without becoming ill. Not all vets do it this way, and that is understandable.