Liver biopsy techniques for adult horses and neonatal foals to assess copper status.

This study evaluated two different methods of liver biopsy in horses and foals to determine their copper status. The methods were judged on their ease of use and impact on the animal, and were found to be safe and effective.

Research Methods

• The researchers evaluated two different techniques for performing biopsies on the livers of horses; the standing, percutaneous, ultrasound-guided, transthoracic liver biopsy for adult horses, and the transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia for foals.
• These techniques were performed on 20 of 24 Thoroughbred mares and 21 of their foals as part of a larger study assessing the effect of copper supplementation on copper status and the prevalence of developmental orthopaedic disease in horses and foals.
• Liver tissues from unrelated horses were also used to investigate the variability in copper distribution within the liver.

Research Findings

• The biopsy technique used on mares was found to be safe and without lasting effects. However, there was an increased risk of viscus penetration when multiple biopsy cores were taken.
• Ultrasound was utilized to identify appropriate candidates for liver biopsies as it was found to help in identifying cases where the large intestine was situated within the biopsy region, therefore revealing conditions not suitable for liver biopsy.
• In foals, there were no serious post-operative adverse effects noted. Moreover, there was no evidence of problems induced by the procedure when the abdomen was examined posthumously at 5 months of age.
• The study of horse livers found copper to be relatively evenly distributed throughout the liver.

Conclusions

• Both techniques studied, standing, percutaneous, ultrasound-guided, transthoracic liver biopsy for adult horses, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia for foals, were identified as convenient and safe methods for obtaining liver tissue to assess copper status in horses.
• The researchers recommended the use of ultrasound for identifying liver tissue, particularly in larger or older mares where access may be more challenging.