Introduction

The cardinal rule of feeding a malnourished or anorectic patient is ‘if the gut works, use it’! This is a tricky proposition in cats who seem more prone to anorexia than dogs as a result of stress (at home or in hospital), finicky eating behaviours and dietary preferences. When these factors are added to an ill cat experiencing gastrointestinal signs, malaise, pain or lethargy, it becomes increasingly challenging to keep these patients at an appropriate plane of nutrition. Yet studies have shown that nutrition plays a key role in the full recovery of critically ill patients.¹ Enteral feeding techniques preserve the mucosal barrier, prevent villus atrophy, help maintain the immunologic function of the GI tract, and can allow owners to treat their pets at home. While pharmacological appetite stimulants and naso-oesophageal feeding tubes are ideal for short-term usage, neither generally allow adequate caloric feeding in severely sick patients and feeding may even be impossible in cats with anatomical or functional problems of the oral cavity or oesophagus.

This lecture will outline basic information for clinicians to consider using feeding methods intended for more long-term use (e.g., oesophagostomy tube vs. gastrostomy tube). It should be emphasised early on that with suitable training, these solutions are achievable for those in the general practice setting.

Oesophagostomy Tube

Oesophagostomy tubes are often favoured for intermediate- to long-term use (>1–2 weeks). Examples of cases which could benefit from this method would include nutritional support for severe orofacial injuries, cases of hepatic lipidosis/cholangitis/acute pancreatitis and for those non-compliant patients requiring long-term oral medications to manage their condition (e.g., mycobacteria infection).

It should be noted that if a patient is anaesthetised for an investigative procedure (e.g., exploratory laparotomy for full-thickness biopsies for suspected gastrointestinal disease), the placement of an oesophagostomy tube should be strongly considered as they can be easily removed if not required.

Oesophagostomy tubes are generally well tolerated by most patients. Because of its large bore (16–18F), it can often accommodate most blenderised diets (cf. naso-oesophageal feeding tubes).

Contraindications

• Primary or secondary oesophageal disorders such as oesophageal stricture, oesophagitis and mega-oesophagus
• Persistent vomiting
• Absent gag reflex

Serious complications seem to be exceptionally rare.² The only minor complication occasionally seen with oesophagostomy tubes is stoma-site infection/granulation tissue^1,2 and (in the author’s experience) continued anorexia due to oesophageal irritation. Prevention of stoma-site infection is usually achieved by daily cleaning of the tube site.

Gastrostomy Tubes: PEG Tubes (Percutaneous Endoscopically Placed Gastrostomy)

Gastrostomy tubes are indicated in patients with chronic diseases requiring long-term/life-time nutritional support such as those suffering from chronic or irreversible diseases affecting the oropharynx or oesophagus. PEG tubes should not be placed when only short-term usage is anticipated (<7 days), in cats considered poor anaesthetic candidates or when complications such as wound healing or severe coagulopathy are present.

Gastrostomy tubes can be placed 1) blind percutaneously (e.g., ELD applicator), 2) surgically during laparotomy or 3) endoscopically.

Percutaneous endoscopically placed gastrostomy (PEG) tubes are often the preferred method of gastrostomy placement because visibility is ideal and the procedure is fast, effective and safe in most circumstances.

The most common complications associated with PEG tubes include insertion-site infection, peristomal pain, peristomal leakage, chewing/dislodgement of the tube by patient, and tube occlusion. Other less common complications include injury to adjacent organs (e.g., spleen, colon, small intestine), bleeding (intraperitoneal, abdominal wall, organs), ‘buried bumper’ syndrome, and gastric outflow obstruction.

Equipment

A standard gastroscope is utilised to facilitate placement of the feeding tube. The commercial kits contain - besides the feeding tube with conical end - the following material: large over-the-needle catheter (16G), double-looped strong suture material (long enough from mouth to side of abdomen, 70–100 cm), scalpel, material to fix feeding tube on outside (clips or suture) and adaptor for feeding syringe.

There are two types of PEG tubes available, commercial kits (adapted from human medicine) which contain all material for quick placement, and “homemade” kits which are cheaper but more cumbersome to build/place and therefore more time consuming. With both ‘kits,’ the placement takes place the same way – a “guide wire” of suture material is pushed via a needle through the abdominal and gastric wall into the gastric lumen, grabbed endoscopically and pulled via oesophagus through the mouth. The PEG is then attached and pulled via the “guide wire” into place. Commercial PEG tubes are either silicone or polyurethane and can withstand gastric acidity for the animal’s lifetime. In cats, 16 Fr to 20 Fr size is used.³ The inner flange is different between different brands but all are suitable for cats.³

A step-by-step guide of PEG tube placement in cats can be accessed for more in-depth instruction.³

Once the PEG is in place, the site is lightly wrapped with occlusive dressing, a body or stretch netting is commonly sufficient in cats and no buster collar needed. Daily cleaning of the stoma with an antibiotic or iodine cream is important. Feeding can be begin 24 hours post-placement after performing a contrast radiograph to confirm the absence of peritoneal leakage. Initially, the cat can be given 5–6 divided meals with an increase in volume, decrease in frequency, over the course of a week. While problems with PEG feeding are rare,^2-4 they can arise and should be dealt with according to guidelines².

PEG tubes can stay in place for many months, even lifelong. A PEG tube must stay in place in place for at least 3–4 weeks to ensure adequate adhesion formation.³ Removal should always occur endoscopically as the inside flange of commercial kits is too large to pass naturally when the tube is cut from the outside.

Low-Profile Button Tubes

These tubes lie flush against the body wall giving a more cosmetic appearance. It also seems to allow for the cat to resume normal activity without heavy bandages or risk of tube dislodgement via entrapment on objects. In the author’s experience, they seem to have a low complication rate and offer high owner satisfaction compared to more traditional tubes.

They can be placed either as a ‘two-step approach’ following the initial placement of a PEG tube, or a ‘one-step approach.’ The latter approach eliminates the initial placement of a traditional PEG tube.

‘Two-Step’ Low-Profile Placement

These tubes can be placed percutaneously after a secure gastropexy and stoma have been achieved using a traditional PEG tube. Stoma tract maturation typically occurs in 4–6 weeks. Low-profile buttons have two types of internal fixation flange: 1) balloon, 2) non-balloon.

In the author’s experience, balloon buttons seem to have a high failure rate due to spontaneous deflation and/or bursting resulting in dislodgement. For this reason, the author recommends the use of a non-balloon buttons due to their resilience to long-term exposure to gastric acid and their superior retention disc compared to balloon material. Due to availability (or lack thereof) of appropriately sized infant-sized low-profile tubes in cats, the author will often choose to place a slightly larger traditional 20F PEG and replace with a smaller 18F x 1.5 cm low-profile non-balloon (AMT Mini-One Button Low Profile). This size seems to be suitable for most breeds/size and BCS. The tube uses a stiff stylet with string/toggle system to aid in flange deployment. Removal also relies on a stiff stylet to straighten the mushroom tip resulting in little resistance during traction.

‘One-Step’ Low-Profile Placement Methods

A one-step method for placing low-profile buttons can be used as an alternative to the above method. This can be achieved via ‘pull technique’ (see One-Step Low Profile, non-balloon button) which is placed in a similar fashion to a normal PEG tube (author’s choice in cats 16G x 1.7 cm with retention discs).

Summary

Enteral feeding devices should be employed early when it is recognised that the patient is not meeting its nutritional and energy needs or requires long-term pharmacological management in a non-compliant patient. Proper tube placement, handling, and client communication are essential for tube longevity and patient safety. Enteral feeding is the preferred method of nutritional support in patients with functional gastrointestinal tracts. Remember, ‘If the gut works, use it!’

References

1.  Saker KE, Remillard RL. Critical care nutrition and enteral-assisted feeding. In: Hand MS, Thatcher CD, Remillard RL, Roudebush P, Novotny BJ, eds. Small Animal Clinical Nutrition. 5th ed. Topeka, KS: Mark Morris Institute; 2010:439–476.

2.  Ireland LM, Hohenhaus AE, Broussard JD, Weissman BL. A comparison of owner management and complications in 67 cats with esophagostomy and percutaneous endoscopic gastrostomy feeding tubes. J Am Anim Hosp Assoc. 2003;39:241–246.

3.  Neiger R, Robertson E, Stengel C. Gastrointestinal endoscopy in the cat: diagnostics and therapeutics. J Feline Med Surg. 2013;15:993–1005.

4.  Armstrong PJ, Hardie EM. Percutaneous endoscopic gastrostomy. A retrospective study of 54 clinical cases in dogs and cats. J Vet Intern Med. 1990;4:202–206.