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veterinary
farriery
2017
Cohort Study

Right dorsal colon ultrasonography in normal adult ponies and miniature horses.

Authors: Siwinska Natalia, Zak Agnieszka, Baron Monika, Cylna Marta, Borowicz Hieronim

Journal: PloS one

Summary

# Editorial Summary: Right Dorsal Colon Ultrasonography in Ponies and Miniature Horses Establishing breed-specific ultrasonographic reference values is essential for accurate clinical assessment, yet most equine abdominal ultrasound protocols rely on data from full-sized horses. Researchers performed standing, unsedated transabdominal ultrasonography on 23 ponies and miniature horses (study group) and 10 Thoroughbreds (control group), measuring right dorsal colonic wall thickness and peristaltic motility at the 10th–14th intercostal spaces, with contractility specifically recorded at the 12th space. Notably, ponies and miniature horses displayed significantly thinner colonic walls (0.27 ± 0.03 cm versus 0.37 ± 0.03 cm in large-breed horses) but substantially higher peristaltic rates (4.05 ± 1.07 contractions per minute compared to 1.7 ± 0.46 in Thoroughbreds), with consistent right dorsal colon visualisation at the 12th intercostal space across all small-breed animals. These findings indicate that practitioners examining ponies and miniature horses require distinct reference parameters to avoid misinterpreting normal physiological variation as pathology; applying large-horse norms to smaller breeds risks both false-positive diagnoses and missed genuine colonic dysfunction.

Read the full abstract on PubMed

Practical Takeaways

  • When performing abdominal ultrasound on ponies and miniature horses, use breed-specific reference ranges for colonic wall thickness and motility rather than values derived from full-size horses
  • The 12th intercostal space is the reliable scanning location for visualizing the right dorsal colon in small breeds during standing unsedated examination
  • Increased peristaltic activity in small breeds is normal and should not be mistaken for pathological colic when interpreting ultrasound findings

Key Findings

  • Right dorsal colon wall thickness in ponies/miniature horses is 0.27 ± 0.03 cm versus 0.37 ± 0.03 cm in Thoroughbreds
  • Peristaltic contractions in small breeds average 4.05 ± 1.07 per minute compared to 1.7 ± 0.46 in large breeds
  • Right dorsal colon is consistently located at the 12th intercostal space in small breed horses
  • Different ultrasonographic reference values are required for small versus large breed horses

Conditions Studied

normal anatomyright dorsal colon