Hepatic Enzyme Profile in Horses.
Authors: Satué Katy, Miguel-Pastor Laura, Chicharro Deborah, Gardón Juan Carlos
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Distinguishing between hepatocellular and cholestatic liver injury in horses relies on interpreting patterns of enzyme elevation, yet practitioners need clarity on which markers best indicate specific pathological processes and timelines. This 2022 review examined six key liver enzymes—sorbitol dehydrogenase (SDH), glutamate dehydrogenase (GLDH), γ-glutamyl transferase (GGT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP)—categorising them by their diagnostic utility and clinical significance. The authors demonstrated that SDH and GLDH predominantly reflect acute hepatocellular damage, whilst GGT specifically indicates biliary necrosis or hyperplasia; AST and ALP conversely suggest chronic disease progression despite being less liver-specific. Diagnostic interpretation requires evaluating multiple parameters simultaneously: the predominant enzyme pattern (hepatocellular versus cholestatic), the magnitude of elevation (mild, moderate, or marked at 5–10-fold or >10-fold above reference range), temporal changes, and whether the course appears acute or chronic. For practitioners managing suspected hepatic disease, this multi-factorial approach enables more targeted diagnostic reasoning and helps differentiate between infectious, inflammatory, metabolic, and toxic aetiologies, ultimately supporting earlier intervention and more precise monitoring of treatment response.
Read the full abstract on PubMed
Practical Takeaways
- •Use SDH and GLDH as your first indicators of acute liver problems in horses; elevations of AST and ALP suggest chronic disease instead.
- •Interpret liver enzyme panels by looking at the pattern (hepatocellular vs. cholestatic) and the degree of elevation rather than single enzyme values to identify the type and stage of liver disease.
- •Track enzyme changes over time to distinguish acute from chronic hepatic disease and monitor treatment response, as acute markers (SDH, GGT, GLDH) change faster than chronic markers (AST, ALP).
Key Findings
- •SDH and GLDH are most specific for acute hepatocellular injury and cholestasis in horses.
- •GGT shows high values in biliary necrosis or hyperplasia, while AST and ALP indicate chronic liver or biliary disease.
- •Enzyme patterns at the blood level can differentiate between various liver pathologies including infectious, inflammatory, metabolic, and toxic types.
- •Diagnostic interpretation of hepatic disease requires assessment of hepatocellular versus cholestatic enzyme abnormality patterns and degree of elevation (5-10 fold or >10 fold above reference range).