Many dogs and cats with critical illnesses do not eat voluntarily so are at risk of weight loss, decreased immune function and poor recovery from trauma and disease. Naso-enteric feeding tubes, either ending in the oesophagus (naso-oesophageal tubes) or stomach (naso-gastric tubes), can provide a balanced diet with sufficient calories to such patients. However, complications can occur following tube misplacement into the respiratory tract, which can be fatal, but little is known about how common this is or the best way of ensuring correct placement.

In a study carried out by Karen Humm and colleagues at the RVC, 97 animals (82 dogs and 15 cats) were prospectively randomised to have either naso-esophageal (n=49; 39 dogs and 10 cats) or naso-gastric tube placement (n=48; 43 dogs and 5 cats). The tube was misplaced into the respiratory tract in three (3.1%) cases. Detection of tube misplacement was best achieved using thoracic radiography, although testing for negative pressure at the thoracic inlet was consistent with the tube in the oesophagus in most (86.2%) cases, while capnography was useful to confirm tracheal placement.

A total of 25 (25.8%) patients had mostly minor complications reported during tube placement, including sneezing (n=12) and nasal bled (n=1). Cardiopulmonary or respiratory arrest occurred in 2 dogs, which was thought to be related to drug use. There was no significant difference in the new-onset regurgitation/vomiting rate, or complications while the tube was in situ between the naso-esophageal and naso-gastric groups.

Take home message

The study concluded that the rate of feeding tube misplacement in the respiratory tract was low, with no difference between complication rates between naso-esophageal and naso-gastric tubes. Thoracic radiography was found to be the optimal method of ensuring correct tube placement, but if not available, other tests such as capnography or assessing for negative pressure at the thoracic inlet or final site could be considered. The choice of tube should be guided by clinician preference, and clients should be warned about possible complications during placement and while in situ.

The paper was published open access in the July 2024 issue of the Journal of Small Animal Practice and can be accessed here: https://doi.org/10.1111/jsap.13729