Previous research has established the development and patterns of sucking behaviour in sheep, as well as factors potentially affecting them. However, in no case the health of the mammary gland of ewes, i.e. possible presence of mastitis, has been taken into account during these studies. In fact, not a single one of all relative research publications has considered examination of mammary secretion samples, to assess mammary health of the experimental ewes. The objective of the present work was to study whether ovine subclinical mastitis potentially influences dam/offspring behaviours during lactation, with a view to standardizing procedures during investigations of these behaviours.