Equis ISSN 2398-2977

Ultrasonography: abdomen

Contributor(s): John Mattoon, Chris Whitton


  • Abdominal ultrasonography can provide information about abdominal structures that cannot be obtained using other diagnostic techniques. 
  • It is an important step in the diagnosis and assessment of abdominal disorders, either for elective examination or as part of the evaluation protocol for colic cases.


  • Sonographic evaluation of suspected disorders of the abdomen, including genitourinary tract, liver, spleen, gastrointestinal system and peritoneal cavity.
  • Guided tissue biopsy   Biopsy: overview   of kidney, liver   Liver: biopsy  and spleen; guided fluid aspiration of some abscesses and cavities.
  • Rapid evaluation of specific structures, especially stomach, duodenum and jejunum, in colic   Abdomen: pain - adult  cases.


  • Non-invasive and can be performed on standing, often non-sedated horses.
  • Readily available, proven technique.
  • Visualization of structures in more detail than possible radiographically   Radiography: overview  .
  • Relatively quick procedure with immediate results in some cases.
  • Reliable, immediate diagnosis of abdominal cryptorchidism   Testis: cryptorchidism  .
  • Can assess areas of the abdomen not accessible for rectal papation in colic cases.
  • Useful for monitoring gastric decompression in colic cases.


  • Needs not only a sound knowledge of abdominal anatomy and the relationships of various structures, including normal variations in location, gas and fluid content, but familiarity with the sonographic appearance of these structures.
  • Clipping may be required for transcutaneous sonography in elective or long-haired cases; transrectal views can only be obtained if horse is big enough for rectal examination.
  • Limited view of liver is possible; variable appearance and location of the spleen; difficult to obtain complete view of both kidneys; gas-filled large colon obscures many abdominal structures.
  • Transrectal imaging not possible in young, fractious or small horses and always carries the same risks of perforation as for rectal palpation   Musculoskeletal: rectal palpation  .


This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login


This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login


This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Sheats M K et al (2010) Use of ultrasound to evaluate outcome following colic surgery for equine large colon volvulus. Equine Vet J 42 (1), 47-52 PubMed.
  • Mueller E & Epstein K (2009) A view into the 'black box': peering through the window with ultrasound and laparoscopy. Equine Vet Educ 21 (1), 31-35 VetMedResource.
  • Menzies-Gow N (2008) Ultrasonography of the normal adult equine abdomen. UK Vet 13 (7), 13-19 VetMedResource.
  • Schambourg M A et al (2006) Use of transabdominal ultrasonography to determine the location of cryptorchid testes in the horse. Equine Vet J 38, 242-245 PubMed.
  • Pease A P et al (2004) Accuracy of increased large-intestine wall thickness during ultrasonography for diagnosing large-colon torsion in 42 horsesVet Radiol Ultrasound 45, 220-224 PubMed.
  • Durham A E et al (2003) An evaluation of diagnostic data in comparison to the results of liver biopsies in mature horsesEquine Vet J 35, 554-549 PubMed.

Other sources of information

  • Reef V B (1998)Equine Diagnostic Ultrasound.W B Saunders, Philadelphia.