Abstract
Background:
Neurological health is a relevant area of animal public health, as perturbations in the activity of neural enzymes have a tendency to mirror animal welfare and environmental stress that will ultimately affect human populations.

Aim:
The aim was to measure serum cholinesterase (ChE) activity in different animal species using a 96-well ELISA assay, with an emphasis on its application as a biomarker of animal welfare within the frame of public health.

Methods:
A linear calibration curve (y = 0.0062x + 0.2011, R² = 0.8187) with nice linearity was achieved and validated the assay to be trustworthy for quantitative enzyme assay. Nine groups of animal serum samples included: rabbit, sheep, cow, fish, cat, chicken, rat, dog, and goat, were collected and assayed to determine variation in cholinesterase levels.

Results:
The findings demonstrated distinct interspecies variations, revealing the highest mean enzyme activity in chickens (6.99 U/L), followed by cats and fish, and the lowest in sheep, goats, and dogs (1.6–1.7 U/L). The results show that the activity of cholinesterase is directly related to the physiological status of animals and may be a highly sensitive biochemical parameter for measuring animal welfare and neurophysiological homeostasis. There could be reduced activity of cholinesterase could be indicative of exposure to neurotoxic chemicals, stress, or starvation, while consistent activity would indicate health and environmental stability.

Conclusion:
From the public health point of view, the study highlights the importance of monitoring cholinesterase activity as being integral to welfare monitoring and environmental watch programs. The ELISA-based assay was shown to be a high-throughput, robust method for determining neurological and welfare status in animals, reaffirming its usefulness under the One Health umbrella that links animal and human well-being.

Key words: Animal public health; Cholinesterase levels; ELISA.