Treatment of chorioptic mange in dairy cows contributes to improved animal welfare.

The present study investigated the impact of antiparasitic treatment for Chorioptes spp. infection on the behaviour and stress of lactating cows. Although chorioptic mange is common, its effects on cow welfare through behavioural and physiological indicators remain unclear. The effects of topical eprinomectin for chorioptic mange on behaviour and salivary cortisol concentrations, indicators of cow welfare, were examined. In Study 1, total lying time after treatment, a key indicator of improved comfort in cows, showed a significant increase of 35 min. In Study 2, itching behaviour (P < 0.05) and salivary cortisol concentrations (P < 0.01) both significantly decreased after topical eprinomectin. All mites were identified as Chorioptes texanus via CO1 gene sequencing. Although no untreated control group was included due to ethical constraints, these results strongly suggest that Chorioptes spp. infection is a physiological stressor that negatively affects behaviour and elevates cortisol concentrations. Timely treatment improves cow comfort and welfare, underscoring its potential relevance to sustainable dairy production.