Trace elements in sheep: history taking

Trace elements impact the health and productivity of UK sheep flocks when supply is not optimal. The consequences of suboptimal supply can result in various clinical presentations (Table 1). However, in some instances, unproven trace element deficiencies and their correction have been lauded as a panacea for all manner of conditions (Hinde, 2020). Therefore, it is important to gather sufficient evidence to support a presumptive diagnosis and justify laboratory test expenditure. These tests are often not as diagnostically defini- tive as we would like (Clark and Wright, 2005) and should be interpreted in conjunction with background evidence. In addition, a better understanding of the factors contributing to each particular presentation of deficiency may improve targeted nutritional management.

BCS, body condition score; MV, Maedi Visna; OPA, ovine pulmonary adenocarcinoma

Gathering such evidence requires thorough history-taking, which will be the focus of this article. This history-taking goes beyond the scope of individuals or groups of animals to encompass a holistic understanding of farm management and geographical factors. These factors may influence the likelihood that a clinical scenario results from a trace element imbalance, thereby moving trace element imbalance up or down a differential diagnosis list.