There are four types of "tube feeding" commonly used in critical
care patients in veterinary medicine: orogastric, nasoesophageal,
gastrostomy, and jejunostomy.
Orogastric feeding is used for the shortest period of time,
generally only a day or two. This is also the most common method
for feeding compromised neonates, who incidentally tend to tolerate
multiple daily feedings better than adults. This method involves
placing a tube at each feeding down the animal's esophagus to its
stomach. Depending on the size of the animal and the size of the
tube used either liquid diets (Clinicare, Vivonex) or a slurry made
from a canned or dry food product may be used.
Nasoesophageal (NE) feeding involves placing a tube through the
animal's nares, or nasal passage, into the esophagus. Another type
of tube that is placed this way is a nasogastric (NG) tube, this
tube also passes through the nares, continues down the esophagus
and terminates in the stomach. The nasoesophageal tube is preferred
because it does not irritate the esophageal sphincter, the round
muscular opening, to the stomach, and therefore is not as likely to
cause regurgitation. The NE tube is best for animals that are
likely to begin eating on their own again in 3-7 days. The
placement of the tube allows the animal to eat on its own if their
appetite begins to return, allowing the veterinary staff to
supplement the diet by feeding through the tube until the animal is
able to eat enough calories to maintain his or her weight. These
tubes are generally of a smaller diameter, and a liquid diet is
administered through the tube.
Gastrostomy and jejunostomy tubes are both placed surgically
while the animal is under general anesthesia. The gastrostomy tube
terminates in the animal's stomach and the jejunostomy tube
terminates in the jejunum, the first section of the animal's small
intestine. These tubes will have an opening, called a port, that is
secured with sutures on the animal's side where the diet is
administered. These tubes are generally large enough in diameter
that the veterinarian can choose between a liquid or slurry diet,
however a jejunostomy tube generally requires an elemental or
liquid diet of basic nutritional components since it bypasses the
digestive action of the stomach.
Michael S. Hand, Craig D. Thatcher, Rebecca L. Remillard and
Philip Roudebush. Enteral-Assisted Feeding. Small Animal Clinical
Nutrition 4th Edition. p371-373, 2000.