Enteral nutrition is a form of assisted feeding which is most commonly used for dogs and cats that cannot eat voluntarily, or have a health condition that results in chronic caloric insufficiency. It is also useful for providing fluid supplementation or for administering medications in intractable animals.
Different types of tubes, diets and nutrition plans are required for animals with different needs.
Use our guide below as a reference to help optimise your patient’s enteral nutrition plans.
Tube feeding can be crucial for maintaining immune function and cellular metabolism. Early nutritional support has proven to reduce hospital stays.
Without proper nutrition, negative health consequences may result:
There are many different feeding tubes, each designed with different diameters and for different locations of insertion. The most appropriate type will be the one that best meets the needs of the patient and the health status of their digestive system
Feeding tubes are widely categorised as either narrow or large diameter tubes. Narrow diameter tubes are nasoesophageal (NE), nasogastric (NG) and jejunostomy (J) located. A liquid enteral diet is needed due to the limited tube size. Larger diameter tubes are esophagostomy (E) and gastronomy (G) related. There is a greater range of diets that can be fed through these tubes. Animals with impaired swallowing reflexes or dysphagia would require gastronomy or jejunostomy.
|
Tube type |
Size |
Advantages |
Disadvantages |
|
Nasogastric (NE) Nasoesophageal (NG) |
Narrow diameter (5 or 8 french) |
|
|
|
Esophagostomy (E-) |
Large diameter (12-14 french) |
|
|
|
Gastrostomy (G-) |
Large diameter (12-14 french) |
|
|
|
Jejunostomy (J-) |
Narrow diameter (5 or 8 french) |
|
|
Creating a personalised plan for each patient optimises the health outcome, minimises pet discomfort and can prevent digestive complications.
Patients will require different types of diets based on their age, species and medical condition. For example, some characteristics to consider may be that:
The type of feeding tube must also be taken into consideration - narrow diameter tubes would require a liquid enteral diet. For larger diameter tubes, commercially canned foods can be diluted and blenderised to form a maintenance diet.
The diet must be designed with the animal’s specific RER (resting energy requirement) in mind, calculated to their current body weight. The calories consumed per day in the diet should add up to the daily RER of the animal. For obese animals, the diet may be intentionally designed to be lower than their current RER to reach their target weight.
Calculating RER:
It is important to calculate the kcal/mL of the feed so that the specific amount of food per meal can be planned and appropriate feeding instructions can be conveyed to the client.
Calculating kcal/mL
The frequency and amount of food per feed depend on many factors regarding the pet’s health history. It is generally better to feed more frequently, with a smaller amount each time, to prevent complications associated with volume overload (diarrhea, vomiting).
Feeding frequency should ideally be every 4-6 hours. This can reduce in frequency to every 6-8 hours once the patient begins to tolerate feedings. Studies recommend splitting the daily RER into 4-6 feeds depending on the animal’s estimated stomach capacities. Most animals with E- and G- tubes can manage 3-6 feedings per day where 5-10ml/kg/feeding is typically tolerated
Patients with a history of anorexia may require a longer and slower ramp-up of feeding to eventually reach the target RER. For example, it may be appropriate to provide the animal with 25-50% of its RER on day 1 and then steadily increase to target RER over the next 2-4 days.
It is important to convey the feeding schedule to the client to optimise compliance and minimise pet complications
Prior to each feeding, it is important to check the patient records and see how they have tolerated recent feeds. Assess the animal’s haemodynamic stability, cardiovascular stability, body temperature, electrolyte levels and identify any recent episodes of vomiting/regurtitation. If the patient check shows the animal is ready to receive the next feed, the integrity of the feeding tube should be investigated.
Pre-feed flush: flush the tube with sterile water to check for position and patency. Administer enough water to ensure the entire tube length is clear of debris and that a cough response would be elicited if the tube has migrated. 5-20mL of water may be needed, depending on the size of the animal and size/length of the tube. It is advised for the vet team to check the minimum volume required so the correct amount is conveyed to clients.
Food administration: a feed generally takes 10-20 minutes to administer. The speed should be slow enough to avoid problems such as regurgitation. An initial observation of the animal’s response is recommended before continuing.
Post-feed flush: the tube needs to be flushed with water to clear any remaining food which may later block the tube. A similar volume to the pre-feed flush would likely be required.
To protect your practice and allow for easy tracking of the pet’s health history, every feed needs to be recorded onto the patient’s hospital chart or clinical records. The volumes of the pre-feed and post-feed flush should be recorded along with the volume of food. The type of food, the tube feed tolerance and any problems experienced during the feed should also be noted.
The feeding tube site should be checked and cleaned regularly, at least once a day, to prevent infections, blockages and other complications.
Inspect the insertion site for:
Tube blockages are common, but can be minimised with correct maintenance. Blockage risk can be greatly reduced by flushing after each feed and ensuring medications are crushed before administration. If a blockage occurs, a syringe can be used to suck the fluid out of the tube, followed by a flush with warm water.
To minimise risk of infection, it is also important to avoid over-wetting the area and to make sure that any materials surrounding the skin are removed.
There can be severe complications associated with tube feeding, however many of these can be managed or prevented with correct feeding and tube maintenance practices.
The most common complications of tube feeding are vomiting and diarrhea. Vomiting is usually due to overaggressive feeding. Decreasing the volume and slowing the administration of each feed should help to correct this. Conversely, diarrhea is often due to an underlying disease or health condition. Feeding gradually can help eliminate potential dietary causes of diarrhea. If a larger feeding tube is being used, adding fiber to the diet can also be beneficial.
Mechanical complications of tube feeding can include tube migration, removal or obstruction. Proper maintenance of the tube is important in minimising these complications. It is important to educate clients about proper home care to help preclude issues: e.g. emphasizing the importance of flushing the tube with water before/after feeding. If the tube becomes occluded, various actions can be performed to amend the blockage. Mechanisms that commonly work include vigorously flushing the tube with warm air or water, infusing carbonated beverages and instilling pancreatic enzymes.
Metabolic complications can be generally avoided if the diet is designed to consider the animal’s RER (resting energy requirement) and any pre-existing health conditions. For example, complications such as hypophosphatemia, arginine deficiency in cats and hyperglycemia can be managed by curating a diet with an appropriate proportion of protein, carbohydrates, and fats.
Bacterial contamination of the enteral diet can lead to illnesses in the pet. It is important to educate clients about the practices of hygienic food storage, such as infusing the diet within 12 hours to minimise the risk of bacterial growth.
To prevent inflammatory complications with gastrostomies and jejustomies, it is also best to leave the tube in for at least 7 days.
Assisted feeding should commence after an animal loses the ability to voluntarily consume sufficient food to maintain health, and continue for as long as necessary under these conditions. It should be discontinued after the patient has recovered the ability to consume and digest food to an adequate level of caloric sufficiency. For gastrostomies and jejunostomies, the tube should only be removed after at least 7 days to prevent potential complications such as peritonitis.