Doi_2026_J.Vet.Med.Sci__

Serum nonspecific esterases, including paraoxonase 1 (PON1), butyrylcholinesterase (BChE), and carboxylesterase (CES), may influence the hydrolysis of some ester-containing drugs. However, data on these enzymes across animal species remain limited. This study compared serum PON1, BChE, and CES activities among dogs (n=6), cats (n=6), micro-mini pigs (n=6), and goats (n=8) using identical assay systems. Serum samples were analyzed using established colorimetric or fluorescent assays, and interspecies differences were evaluated using the Steel-Dwass test. PON1 activity was highest in goats, BChE activity was highest in dogs, and CES activity was highest in cats. These findings demonstrate distinct interspecies profiles of serum nonspecific esterase activities and provide baseline data for future studies investigating species differences in the metabolism of ester-containing compounds.