This procedure does require short term sedation for cats since they commonly have esophagostomy tubes placed. These tubes go into the neck and lie down the esophagus. They are meant to be a temporary assistance for the cat with a medical problem that is not eating sufficiently. The cats are fully capable of eating with the tube in place. The tube is typically also used for medication administration. Once the cats are eating at least 2/3 of their normal diet on their own, the tube can be easily removed in the office. Some people prefer to leave the tube in place until the cats are no longer on medication.
For dogs, who have much thicker neck muscles and generally longer snouts, we typically place a tube into the stomach endoscopically. This allows both food and medication to be given as in the cat but removal does require sedation.