Ultrasonographically visible hepatic location in clinically normal horses.

This research conducted ultrasonographic evaluation of the liver on 58 clinically normal horses, to better understand where the liver should be visible and how factors like age, breed, weight and body condition might affect liver visualization. Results showed that liver should consistently be visible on a horse’s right side; lack of visibility on the left does not suggest a clinical issue. Older horses, particularly those aged 24 years and above, were found to have reduced liver dimensions.

Objective and Methods

• The study aimed to investigate hepatic ultrasonographically visible locations (HUVL) within horses, with a focus on how the visibility and position of the liver may change based on various factors such as breed, age, weight and body condition score (BCS).
• The team employed a prospective observational methodology in which they used ultrasound to examine the livers of 58 clinically normal horses with no prior history of liver disease.
• Measurements and observations taken during these ultrasonographic evaluations included the most forward and backward intercostal spaces (ICS), the total number of ICS where the liver could be visualised, and the lowermost extent of the liver in the body.

Findings

• The team found that the liver was visible on the right side in nearly all horses (97%). On the left, it was visible in slightly fewer (71%), and both sides yielded visible results in around two-thirds (67%) of the cases.
• The liver was not visible beneath the costochondral junction (where the ribs meet the cartilage).
• Significantly fewer ICS on the horse’s right side showed visible liver among older horses (half of the ICS) compared to their younger counterparts (7 ICS).

Conclusions

• The researchers concluded that the visibility of the liver consistently on the right side is expected during an ultrasound procedure. However, the non-visibility on the left does not typically indicate a clinical concern.
• On the other hand, decreased liver dimensions seemed to be an attribute found among older horses, particularly those 24 years and older. This information can be helpful during ultrasound evaluations in determining normal liver visibility and size ranges and noting when deviations from these may indicate potential concerns.