Assessing the relationship between incisor wear, age, and body condition in Dohne Merino ewes (Ovis aries)

Sheep (Ovis aries) are stoic, prey animals that have evolved to mask signs of pain and vulnerability, making behavioural indicators of poor welfare difficult to detect. Body condition scoring (BCS) remains one of the most practical, animal-based indicators of chronic undernutrition and compromised welfare in grazing ruminants. Disruption of the incisor apparatus due to dental disorders or tooth loss can impair grazing efficiency, resulting in reduced nutritional intake and contributing to poor body condition. Despite this, there has been little research into the prevalence or welfare impact of dental disorders in sheep. This preliminary study aimed to assess the prevalence of incisor wear in extensively grazed Dohne Merino ewes, examine its distribution across age groups, and evaluate associations with bodyweight and BCS. A total of 818 ewes aged 2 to 10 years were evaluated during routine husbandry. Incisor wear was scored based on dentine exposure using a 0-3 ordinal scale. BCS was determined through hands-on palpation, and liveweight was recorded. Wear affecting more than one-third of tooth enamel was present in at least one incisor in 99% of ewes over five years of age. Greater incisor wear was significantly associated with lower bodyweight and BCS in ewes over two years, irrespective of age. These findings underscore the potential role of incisor wear as a contributing factor to nutritional compromise and welfare risk in older sheep. Monitoring incisor health may facilitate more accurate welfare assessments and enhance management strategies in extensive systems.