The pathology of a case of biliary atresia in a foal.

The research article details the autopsy results of a 4-week-old foal suffering from biliary atresia that had exhibited signs of hepatic failure. The pathology report provides a comparison of this condition in the foal to both extrahepatic and intrahepatic biliary atresia in humans, while also presenting evidence suggesting an extrahepatic origin for the case under examination.

Case Presentation

• An American Saddler foal around 4-weeks-old was subjected to autopsy, following an illness marked by symptoms suggestive of liver failure.
• Significant physical changes were observed in the liver, which was highly enlarged, had a patchy appearance, and had hardened.
• The foal displayed bile stasis, indicating a halt in the flow or release of bile.
• In a healthy liver, distinct lobules or sections are noticeable, but in this foal, this lobular distinction was missing and large bile ducts did not appear to be present in the liver sections.

Associated Conditions

• Apart from the hepatic lesion, the foal also had moderate ascites (an abnormal accumulation of fluid in the abdomen), hydrothorax (fluid in the pleural cavity), and hydropericardium (fluid around the heart).
• Mild anasarca, a condition of severe, generalized edema, and intramuscular edema or swelling within multiple muscles were also observed.

Diagnosis

• The peculiar histopathological features of the liver, such as bile duct proliferation and extensive replacement fibrosis, led to the diagnosis of biliary atresia.
• This condition causes a blockage in the ducts (tubes) that carry bile from the liver to the gallbladder, and it is typically seen in infants.

Comparison With Human Biliary Atresia

• In humans, biliary atresia can be either extrahepatic (occurs outside the liver) or intrahepatic (within the liver).
• The foal’s condition was likened to these two types, and evidence was presented that pointed towards an extrahepatic origin in this case.