An observational study involving ewe postmortem examination at a fallen stock collection centre to inform flock health interventions

Abstract

Effective sheep flock health plans must be underpinned by flock-specific diagnostic information and should make use of wider national flock health information. However, information on disease prevalence at flock level is often incomplete. This is despite the fact that protocols to diagnose common sheep diseases are well established and cost effective. Annual ewe mortality rates in the UK are estimated at 3–8 per cent (Johnston and others 1980, Scott 2007). The profile of diseases which contribute to mortality and involuntary culling in adult ewes in the UK flock is at present probably best estimated using Veterinary Investigation Diagnosis Analysis (VIDA) data (Gibbens and others 2008). This is generated by the Animal Health Veterinary Laboratories Agency (AHVLA) endemic disease scanning surveillance programme, which examines 500–700 ewes annually (VIDA 2012). However, the sample size, especially for carcases, is small, and the programme may have inherent biases (Nevel and Stark 2009) with under-representation of some important endemic diseases. By law, all fallen stock from UK farms must be collected for appropriate disposal by a licensed collector. This study aimed to investigate the diagnostic potential of this material, with an emphasis on adult ewes, and to consider how such information might be applied to improve sheep health, welfare and productivity. Between February 2012 and January 2013, a total of 106 adult ewes, collected from farms throughout the northeast of England, were examined postmortem during 11 sessions at a fallen stock collection centre. All postmortem examinations were performed by two experienced veterinary surgeons including at least one of the authors, whose competence in postmortem examination was gained during six years at …