There are 2 main "Golden Rules" of nutrition: 1. If the gut works, use it, and 2. Keep it simple.
There are several different techniques available that facilitate "using the gut". These include forced feeding, appetite stimulation, and tube feeding. Feeding tubes offer a means to provide nutrition to an animal that is unable or unwilling to consume food. Placing a tube within the gastrointestinal tract may provide enteral feeding. Such tubes include orogastric, nasoesophageal, pharyngostomy, esophagostomy, gastrostomy, and enterostomy tubes.