A feeding tube may be needed in cases where a pet cannot or will not eat for an extended period of time. There are basically four kinds of tubes that are selected for different situations. Conditions wherein a feeding tube may be used include newborns that are not thriving and need supplemental nutrition, hepatic lipidosis in cats, and fractures and cancers of the jaw. Nutrition and medications can be delivered via the tube directly into the stomach.
The most temporary type of feeding tube is an orogastric tube. This process is performed without anesthesia. A mouth gag is placed between the teeth to prevent the pet from chewing, and a red rubber tube is passed through the mouth, down the esophagus, and into the stomach. Liquefied canned food is drawn into a large syringe and injected through the tube. An entire meal can be delivered in a few seconds. The tube is immediately removed. This method is only used when supplemental feeding will last 1 or 2 days. Complications include vomiting while pulling the tube because of the gag reflex and the risk of aspiration of food into the lungs. This process can be quite stressful to the animal as well.
Another method to deliver calories is to insert a nasogastric feeding tube. This usually does not require anesthesia. A small diameter rubber tube is passed through one nostril, down the esophagus, and into the stomach. Liquefied food can be administered through this tube several times a day. An Elizabethan collar is worn to prevent the pet from removing the tube with a paw. Drawbacks of this method are that the food must be watered down, and thus is not calorie-dense. Also, the tube can be vomited up. When this occurs, the pet will chew off the end of the tube that is hanging out of the mouth, and the owner may not be aware. During the next feeding, liquefied food is squirted into the throat instead of the stomach; and there is a risk of aspiration into the lungs. Sometimes a nasogastric tube is used for a couple of days in order to stabilize an animal before an anesthetic can safely be administered to place a better type of feeding tube.
An esophagostomy / pharyngostomy tube is a better alternative to the nasogastric feeding tube, but it does require anesthesia to place. It is a larger bore tube that can accept blenderized food (more calorie-dense), and it is passed into the esophagus through an incision from the side of the neck. The tube is sutured and bandaged in place and is generally well tolerated. It can be left in place for weeks. This type of tube can also be vomited, so the same risk of aspiration exists as with a nasogastric tube. Also, infection can occur at the incision requiring removal of the feeding tube.
The best type of feeding tube is called a percutaneous endoscopic gastrotomy (PEG) tube. It also requires the pet to be anesthetized for placement. An incision is made through the abdominal wall and directly into the stomach. A balloon-like cuff on the end seals the tube to the stomach wall, preventing leakage of food into the abdomen. Unlike other feeding tubes, it cannot be vomited and the risk of aspiration is much lower. A PEG tube can remain in place for a year or more.