Which liver enzyme is normally elevated in growing foals and should not be overinterpreted if it is high?

• A. ALP
• B. ALT
• C. AST
• D. GGT

Answer: (A)

Alkaline phosphatase rises in growing foals because bone formation is very active during growth, and osteoblasts produce a bone-specific ALP isoenzyme. This means ALP can be high even when the liver is normal, so a high ALP in a foal should not be interpreted as liver disease without considering the growth status and other liver indicators. In contrast, enzymes like ALT and AST indicate hepatocellular injury when elevated, and GGT is more related to biliary function, so they’re used differently in assessing hepatic health. So the enzyme normally elevated in growing foals and not overinterpreted if high is alkaline phosphatase.