Distribution of lamb carcass condemnations due to jaundice over six years in a slaughterhouse in the Northeast of Spain

Since 2020, an increase in carcass condemnations in lambs due to jaundice has been noticed in some slaughterhouses in the Northeastern region of Spain. Therefore, data from 479,055 “Ternasco” lambs (2–3 months old lambs with a live weight of 21–23 kg) slaughtered at Mercazaragoza slaughterhouse (Zaragoza, Spain) were analysed. The data belonged to two companies and were collected between January 2018 and December 2023. The criteria studied included the company of origin, date of slaughter and the cause of condemnation. A total of 2661 lambs (0.56 %) were condemned, with 943 of them being condemned due to jaundice (0.20 %). Jaundice was the main cause of carcass condemnation, accounting for 35.44 % of total condemnation during the study period, with a progressive increase from 2018 to 2021, followed by a slight stabilisation in the subsequent years. A clear pattern was also evident, with more than half (57.69 %) of these condemnations occurring between May and August each year, becoming particularly pronounced from 2020 onwards. Condemnations due to jaundice were the main cause of carcass condemnation in both companies. Based on the seasonality associated with the active period of ticks and previous studies performed in the area, the possible implication of Anaplasma ovis infection in affected lambs is discussed. Further studies are needed to understand the underlying causes and their significance.