Clinical Signs as an Indication of the Presence of Gastric Ulcers in Horses: True or False?

Overview

• This study examined the relationship between clinical signs and the presence of gastric ulcers in horses, focusing on different types of Equine Gastric Ulcer Syndrome (EGUS).
• It aimed to determine how common gastric ulcers are in pleasure and breeding horses and whether specific clinical signs reliably indicate the presence of these ulcers.

Background

• Equine Gastric Ulcer Syndrome (EGUS) includes two main types of diseases affecting horses: Equine Squamous Gastric Disease (ESGD) and Equine Glandular Gastric Disease (EGGD).
• EGUS is prevalent worldwide, particularly in racehorses and those under heavy training.
• Clinical signs of gastric ulcers are often vague, nonspecific, or absent, making diagnosis based on symptoms challenging.

Study Objectives

• To quantify the percentage of pleasure and breeding horses with clinical signs compatible with gastric ulcers.
• To correlate these clinical signs with the presence of ESGD, EGGD, or both simultaneously.
• To investigate how factors like breed, sex, and activity level influence disease development and symptom presentation.

Methods

• Retrospective study involving 1125 adult horses.
• Clinical signs categorized into three groups:
  • Gastrointestinal tract signs (GIT)
  • Performance and behavior signs (PER)
  • Weight loss (WL)
• Endoscopic examination used to diagnose ESGD and EGGD, with ESGD severity graded on a scale from 2/4 to 4/4.
• Data on breed, sex, and activity type (pleasure or breeding) collected for correlation analyses.

Key Findings

• Only 12% of horses showed clinical signs possibly related to gastric ulcers:
  • 6% had gastrointestinal signs
  • 1% had performance/behavior signs
  • 5% exhibited weight loss
• Presence of gastric ulcers was high despite low clinical sign prevalence:
  • 63% diagnosed with ESGD with varying severity (22% grade 2/4, 11% grade 3/4, and 30% grade 4/4)
  • 32% diagnosed with EGGD
• Warmblood horses and geldings more frequently showed clinical signs compared to other breeds and sexes.
• Associations between clinical signs and diseases:
  • Weight loss correlated with both presence and severity of ESGD and presence of EGGD.
  • Gastrointestinal signs correlated only with presence and severity of ESGD.
  • Performance and behavior signs correlated with ESGD severity and EGGD presence.
• Activity type was a major risk factor influencing disease development and modulated the effect of breed and sex.
• EGGD showed a limited effect on clinical signs compared to ESGD, suggesting less obvious symptom manifestation.

Conclusions

• Despite a high prevalence of gastric ulcers in horses not typically regarded as high risk, only a small percentage displayed clinical signs.
• The expression of clinical signs may depend on both the presence and severity of ulcers, especially ESGD.
• Limited clinical sign manifestation in EGGD highlights current gaps in understanding the clinical significance of lesions in the glandular mucosa, especially when hyperemia alone is present.
• Further research is needed to better understand EGGD’s impact on clinical symptoms and to improve diagnostic interpretation.

Implications for Horse Health Management

• Relying solely on clinical signs to diagnose gastric ulcers in horses may be insufficient due to low symptom prevalence despite high ulcer rates.
• Endoscopic examinations remain critical for accurate diagnosis of EGUS.
• Management strategies should consider breed, sex, and activity level as risk factors for gastric ulcer development.
• Greater awareness is needed about glandular gastric disease and its clinical relevance in equine practice.