In a young animal with a swollen navel, a single hepatic lesion indicates infection via which route?

In a young animal with a swollen navel, a single hepatic lesion indicates infection via which route?

• A. Portal vein
• B. Hepatic artery
• C. Umbilical vein
• D. Biliary tract

Answer: (C)

In neonates, infection that starts at the umbilicus can travel directly into the liver via the umbilical vein. The umbilical vein carries blood from the placenta to the fetal liver, so if pathogens invade the umbilical stump, they can be carried straight to the liver and form a localized, focal lesion near the porta hepatis. This direct conduit from the navel explains a single hepatic lesion. In contrast, spread through the portal vein would reflect infection from the gut and typically produces multiple liver lesions rather than a single focus; infection via the hepatic artery implies widespread hematogenous seeding rather than a direct umbilical source; biliary tract infections originate in the bile ducts and present differently, not as a solitary hepatic lesion linked to the umbilicus.

In neonates, infection that starts at the umbilicus can travel directly into the liver via the umbilical vein. The umbilical vein carries blood from the placenta to the fetal liver, so if pathogens invade the umbilical stump, they can be carried straight to the liver and form a localized, focal lesion near the porta hepatis. This direct conduit from the navel explains a single hepatic lesion.

In contrast, spread through the portal vein would reflect infection from the gut and typically produces multiple liver lesions rather than a single focus; infection via the hepatic artery implies widespread hematogenous seeding rather than a direct umbilical source; biliary tract infections originate in the bile ducts and present differently, not as a solitary hepatic lesion linked to the umbilicus.