Retrospective endoscopic assessment of complications associated with nasogastric intubation in horses at a referral hospital.

Overview

• This study evaluated the frequency and types of complications seen in horses after nasogastric intubation by using endoscopic examination at a veterinary referral hospital.
• It identified how often complications occur, whether they cause clinical signs, and what risk factors might be involved.

Study Objectives and Methods

• The primary goal was to characterize the incidence of complications confirmed via endoscopy following nasogastric intubation, and to identify associated risk factors.
• Researchers retrospectively reviewed medical records from March 2021 to March 2025 of horses that had at least one nasogastric intubation within 3 days prior to an endoscopic exam.
• Data recorded included:
  • Horse demographics (signalment)
  • Medical history and clinicopathologic data
  • Details of nasogastric intubation procedures
  • Reason for endoscopy
  • Treatment provided
  • Outcome after intubation
• Complications were categorized by anatomical regions:
  • Nasopharyngeal
  • Esophageal
  • Gastric
• Two categories of complications were defined:
  • Clinical complications: those causing clinical signs prompting the endoscopic exam
  • Subclinical complications: incidentally observed during endoscopy performed for other reasons without related clinical signs

Key Findings

• A total of 94 horses met study inclusion criteria.
• Complications were observed on endoscopy in 25 out of 94 cases (~26.6%).
• Majority of complications (68%) were subclinical and found incidentally.
• By region:
  • Nasopharyngeal complications most commonly associated with clinical signs: 60% of nasopharyngeal cases showed clinical signs.
  • Esophageal complications: 33% showed clinical signs.
  • Gastric complications: none showed clinical signs.
• Horses with complications tended to be smaller in body weight:
  • Median weight of horses with complications was 430 kg (95% CI: 365 to 482 kg).
  • Horses without complications had a median weight of 518 kg (95% CI: 486 to 548 kg).
• Horses with complications also showed increased numbers of band neutrophils, which can indicate inflammation or infection.
• There was no association between complications and:
  • Whether intubation was done prior to referral
  • Number of intubations performed
  • Presence of an indwelling nasogastric tube

Conclusions and Clinical Significance

• About one quarter of horses undergoing endoscopy within 3 days of nasogastric intubation had subclinical mucosal or anatomical complications, most of which did not produce clinical signs.
• Clinical complications—that is, those causing symptoms—were relatively uncommon post-intubation.
• Smaller horses may be at a higher risk to develop subclinical complications after nasogastric intubation.
• Routine nasogastric intubation is generally safe, but endoscopic evaluation can detect unexpected subclinical injuries.
• This information is valuable for veterinarians managing equine cases with nasogastric tubes, helping to balance benefits of intubation with awareness of possible mucosal injury.

Implications for Practice

• Routine use of nasogastric intubation in horses is not commonly associated with clinical complications.
• Endoscopic monitoring may help identify mucosal injuries that are otherwise unnoticed, especially in smaller horses.
• Veterinarians should consider body weight and inflammatory markers when assessing risk and managing nasogastric intubation cases.
• Further studies could help determine if specific techniques or preventative measures might reduce subclinical injury rates, especially in smaller horses.