📄 Original Research · RVC · 2026

Nasoesophageal & Nasogastric Tube Position in Dogs & Cats

A first-of-its-kind interactive training module based on the landmark study introducing and validating radiographic guidelines to accurately identify feeding tube placement in small animal patients.

Andrea Vila Cabaleiro1, Dan G. O'Neill2, Alessia Cordella3, Federico R. Vilaplana Grosso4,
Sara Gioele Rizzo5, Hannah L. Matson1, Federica Porcarelli1, Jade C. Bosher6, Vedant S. Matkar1,
Rachael G. Duggan1, Alessia Diana7, Emmelie Stock8, Harriet Pearce9, Ella Fitzgerald1
1Dept of Clinical Sciences & Services, The Royal Veterinary College, University of London, UK · 2Pathobiology & Population Science, The Royal Veterinary College, UK · 3University of Pennsylvania School of Veterinary Medicine, USA · 4Dept of Small Animal Clinical Sciences, University of Florida, USA · 5Ospedale Veterinario i Portoni Rossi, Bologna, Italy · 6Companion Care Eastbourne, UK · 7Dept of Veterinary Medical Sciences, University of Bologna, Italy · 8Faculty of Veterinary Medicine, Ghent University, Belgium · 9The Ralph Veterinary Referral Centre, Marlow, UK
Published in Veterinary Radiology & Ultrasound · 2026;67:e70138 · DOI: 10.1111/vru.70138
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📊 Study at a Glance
0
Radiographs reviewed
0
Institutions involved
0
Blinded interpreters
0
Guideline criteria
Accuracy before guidelines 82.1%
Accuracy after guidelines 95.8%
Inter-rater agreement (post) 0.86 κ
🔬 Clinical Background

Why Does Tube Placement Verification Matter?

Inadvertent tracheal placement of nasoesophageal or nasogastric tubes can cause life-threatening complications. Radiographic confirmation is the standard practice — but until now, no standardised veterinary guidelines existed.

🍽️
Enteral Nutrition is Essential
Early enteral feeding is widely recommended in veterinary medicine to reduce morbidity and mortality in hospitalised dogs and cats. Nasoesophageal (NE) and nasogastric (NG) tubes are the primary route for short-term nutritional support.
⚠️
Tracheal Misplacement is Dangerous
Inadvertent placement into the trachea can cause aspiration pneumonia, pulmonary haemorrhage, and pneumothorax — all potentially fatal if not promptly identified and corrected.
🩻
Radiography is Standard Practice
Radiographic confirmation is considered the standard practice in both human and veterinary medicine for confirming tube position. Alternative methods (pH testing, capnography, negative pressure testing) have limited evidence supporting their reliability.[1,2]
📋
No Prior Guidelines Existed
Despite widespread radiographic use, no standardised veterinary guidelines existed for radiographic projection, collimation, and tube evaluation — leading to inconsistent, experience-dependent interpretations.
🎯
The Study Objective
This diagnostic accuracy study — the first of its kind — aimed to introduce and validate novel radiographic guidelines for accurate identification of NE/NG tube position, tested by interpreters of varying clinical experience.
✅
The Result: Validated Guidelines
The novel three-point radiographic checklist significantly improved correct tube position identification from 82.1% to 95.8%, and nearly eliminated "uncertain" assessments, from 14.1% down to just 2.4%.
📐 The Three-Point Guidelines

Radiographic Criteria for Correct Tube Placement

Obtain a single lateral cervical and thoracic radiograph and apply these three criteria systematically to confirm correct oesophageal tube placement in dogs and cats.

RVC Infographic – Correct Nasoesophageal/Nasogastric Tube placement in Dogs and Cats: Radiographic verification. Step 1: Obtain lateral thoracic radiograph. Step 2: Apply 3-point guidelines – 1. Dorsal to larynx, 2. Not complete superimposition with the trachea, 3. Dorsal to carina.

Vila Cabaleiro A, O'Neill DG, Cordella A, et al. (2026) 'Introduction and Validation of Radiographic Guidelines for Identification of Nasoesophageal and Nasogastric Tube Position in Dogs and Cats', Veterinary Radiology & Ultrasound, 67(1), e70138.  ·  DOI: 10.1111/vru.70138  ·  © Royal Veterinary College

📷 Paper Figures

Figures from Vila Cabaleiro et al. (2026)

Representative lateral cervical and thoracic radiographs demonstrating correct oesophageal placement and tracheal misplacement of nasoesophageal tubes in dogs and cats. CT images illustrating the anatomy of the lamina of the cricoid cartilage. Click any image to enlarge.

Figure 1 from Vila Cabaleiro et al. 2026
🩻 Oesophageal Placement — Dog

FIGURE 1 | (A–C) Left lateral cervical and thoracic radiograph of a skeletally mature large-breed dog, including the larynx, showing a nasoesophageal tube positioned in the oesophagus (A). The tube exhibits incomplete superposition over the tracheal lumen and is located dorsal to the mineralised lamina of the cricoid cartilage (purple arrow) and the carina (white arrow). Transverse (B) and sagittal (C) CT images of a dog, obtained using a bone algorithm, clearly depict the lamina of the cricoid cartilage (purple arrows).

Figure 2 from Vila Cabaleiro et al. 2026
🩻 Oesophageal Placement — Cat

FIGURE 2 | (A–C) Left lateral cervical and thoracic radiograph of a skeletally mature domestic shorthair cat, including the larynx, showing a nasoesophageal tube positioned in the oesophagus (A). The tube exhibits incomplete superposition over the tracheal lumen and is located dorsal to the lamina of the cricoid cartilage (purple arrow), which is not mineralised, and the carina (white arrow). Transverse (B) and sagittal (C) CT images of a cat, obtained using a bone algorithm, clearly depict the lamina of the cricoid cartilage (purple arrows).

Figure 3 from Vila Cabaleiro et al. 2026
⚠️ Tracheal Misplacement — Dog

FIGURE 3 | Right lateral cervical and thoracic radiograph of a skeletally mature small-breed dog, including the larynx, showing a nasoesophageal tube incorrectly positioned in the trachea. The tube is superimposed over the nasopharynx, laryngopharynx, and tracheal lumen, passing through the laryngeal lumen (purple arrow) and extending to the carina (white arrow) before following a caudodorsal bronchial path.

Figure 4 from Vila Cabaleiro et al. 2026
⚠️ Tracheal Misplacement — Cat (tube short of carina)

FIGURE 4 | Left lateral cervical and thoracic radiograph of a skeletally mature domestic shorthair cat, including the larynx, showing a nasoesophageal tube incorrectly positioned in the trachea. The tube is superimposed over the nasopharynx, laryngopharynx, and tracheal lumen, passing through the laryngeal lumen (purple arrow). The caudal tip of the tube does not reach the carina (white arrow). This radiograph highlights the importance of including the larynx as an additional confirmation point when the tube does not extend to the carina.

Figure 5 from Vila Cabaleiro et al. 2026
⚠️ Tracheal Misplacement — Cat (larynx not visible)

FIGURE 5 | Right lateral cervical and thoracic radiograph of a skeletally mature British Shorthair cat in which the larynx is not visible and the nasoesophageal tube is incorrectly positioned in the trachea. The tube is superimposed on the tracheal lumen (dorsal location in the thoracic inlet), and its tip extends just beyond the carina. Before guideline provision, the radiology intern and both emergency and critical care residents classified the position as “uncertain,” whereas the two fourth-year students and the general practitioner correctly identified tracheal placement. After guideline provision, all six interpreters correctly identified tracheal placement. This case emphasises the importance of including the larynx in routine tube-check radiographs, as it may provide the only definitive landmark when the tube tip does not reach the carina.

Figures reproduced from: Vila Cabaleiro A et al. Veterinary Radiology & Ultrasound. 2026;67:e70138. DOI: 10.1111/vru.70138

📊 Study Results

What the Data Shows

256 radiographs. 6 interpreters. 2 assessment rounds. The results clearly demonstrate that these guidelines work — across all experience levels, species, and clinical settings.

🎯 Correct Identification Rate
Esophageal tubes — Before guidelines 88.8%
Esophageal tubes — After guidelines 98.7%
Tracheal tubes — Before guidelines 75.3%
Tracheal tubes — After guidelines 92.8%
Overall — Before guidelines 82.1%
Overall — After guidelines 95.8%

All improvements: p < 0.001

❓ "Uncertain" Assessment Rate
Overall "uncertain" — Before guidelines 14.1%
Overall "uncertain" — After guidelines 2.4%
Esophageal uncertain — Before guidelines 8.9%
Esophageal uncertain — After guidelines 0.8%
Tracheal uncertain — Before guidelines 19.4%
Tracheal uncertain — After guidelines 4.1%
0.59
Fleiss κ · Before guidelines
Moderate agreement
0.86
Fleiss κ · After guidelines
Almost perfect agreement
🐾 Species Comparison

Dogs vs. Cats — How Did Guidelines Impact Each?

Species significantly influenced diagnostic confidence and accuracy, with an interesting reversal after guideline introduction.

🐕
Canine Radiographs

186/256 (72.7%) radiographs. Largest-ever sample across toy to giant breeds. Tracheal misplacements were predominantly canine (110/127 cases, 86.6%).

Overall accuracy (all) 88.22%
Post-guideline accuracy 94.98%
Uncertain (post) 2.60%
Larynx included 39.2%
🐈
Feline Radiographs

70/256 (27.3%). Predominantly domestic shorthair. Despite narrower mediastinum and reduced radiographic contrast, guidelines performed excellently.

Overall accuracy (all) 90.83%
Post-guideline accuracy 97.86%
Uncertain (post) 1.90%
Larynx included 41.4%
🧠 Knowledge Check

Test Your Understanding

Apply what you've learned about the three-point radiographic guidelines with these clinical scenario questions.

🏥 Clinical Application

Using the Guidelines in Practice

This interactive checklist walks you through the complete tube position assessment. Click each step as you complete it during a real radiographic assessment.

📋 Tube Check Radiographic Protocol
✓
Obtain lateral cervical + thoracic radiograph
Single projection covering nose to caudal thorax. Ensure patient is in true lateral recumbency.
✓
Confirm larynx is visible (if included)
Locate the cricoid cartilage — especially important when tube doesn't reach the carina.
✓
Criterion 1: Is tube dorsal to larynx?
Tube should pass dorsal to the cricoid cartilage lamina. Ventral passage = tracheal placement.
✓
Criterion 2: Is tube separate from tracheal lumen?
Look for incomplete superposition. A clearly separate or partially overlapping tube is esophageal. Full overlap = red flag.
✓
Locate the carina on the radiograph
The carina is visible as the tracheal bifurcation. Present in 93.3% of tube check radiographs.
✓
Criterion 3: Is tube dorsal to the carina?
Tube should lie dorsal to the carina. A tube going through the carina ventral to the dorsal wall is misplaced.
✓
Synthesise all three criteria and document
When criterion 3 is met (tube dorsal to the carina), criterion 2 is implicitly confirmed and oesophageal placement can be concluded with confidence. Criterion 1 applies when the tube does not reach the carina: dorsal to the cricoid cartilage lamina = oesophageal; through the laryngeal lumen = tracheal. Always include the larynx in the radiographic field.
⚡ Complications of Tracheal Misplacement

Inadvertent tracheal placement can cause immediately life-threatening complications. These are the documented consequences:

🫁
Aspiration Pneumonia
🩸
Pulmonary Haemorrhage
💨
Pneumothorax
👥 Who Benefits From These Guidelines?
  • ✓Veterinary students — structured criteria reduce reliance on pattern recognition experience.
  • ✓General practitioners — clear decision points for a less commonly assessed procedure.
  • ✓Rotating interns — consistent framework during early clinical exposure across varied cases.
  • ✓Emergency & critical care clinicians, residents and interns — rapid systematic approach for busy clinical environments.
  • ✓Radiologists — standardised reporting language improves inter-rater agreement (0.59 → 0.86 κ).
🏆 Conclusion & Clinical Impact

This study is the first to establish radiographic guidelines for the accurate identification of nasoesophageal and nasogastric tube positions in dogs and cats. The three-point checklist is rapid, systematic, and reliable — demonstrating strong clinical benefit by improving accuracy from 82.1% to 95.8% and nearly eliminating "uncertain" assessments. Critically, it works across all experience levels, both species, and a wide range of breed sizes. These guidelines should become standard practice in any veterinary setting where enteral tube feeding is used.

p < 0.001 +13.7% overall accuracy κ: 0.59 → 0.86 Uncertain: 14.1% → 2.4% Validated in dogs & cats Multi-institutional design