A comparison of liver sampling techniques in dogs

Area of Science:

• Veterinary Pathology
• Comparative Histology
• Diagnostic Accuracy

Background:

• Accurate histopathologic interpretation of canine liver samples requires optimal sampling techniques.
• Current methods for obtaining liver biopsies in dogs lack consistent adequacy for diagnosis.

Purpose of the Study:

• To compare the histopathologic results of liver samples obtained via punch, cup, and 14-gauge needle biopsy.
• To evaluate the diagnostic concordance of these techniques against large wedge samples collected during necropsy.

Main Methods:

• A prospective study involving seventy dogs undergoing necropsy.
• Liver specimens were collected using an 8 mm punch, a 5 mm cup, and a 14-gauge needle from the left lateral lobe.
• Larger wedge samples from the same lobe served as the histologic standard for comparison.

Main Results:

• Mean portal triads per sample: needle (2.9), cup (3.4), punch (12), necropsy (30.7).
• Diagnostic agreement with necropsy samples: needle (66%), cup (60%), punch (69%).
• No significant difference in agreement proportions between needle, cup, and punch biopsy methods.

Conclusions:

• Liver biopsy interpretation in dogs is unlikely to vary if samples contain 3-12 portal triads.
• All tested biopsy methods demonstrated relatively low accuracy when compared to large necropsy samples.
• Further research may be needed to improve the accuracy of canine liver biopsy sampling techniques.