Shoulder lesions in sows: A review of their causes, prevention, and treatment

Abstract

Severe shoulder lesions in sows are manifested as ulcers comparable to pressure ulcers in humans. In sows, shoulder lesions appear on the skin overlying the bony prominence of the scapula, and are most commonly observed in the first weeks of lactation. Shoulder ulcers arise due to prolonged compression of blood vessels around the tuber of the scapular spine when the sow is lying, leading to insufficient blood circulation, necrosis, and subsequent ulceration. Due to the nature of shoulder lesions and their estimated occurrence (5%-50% of breeding sows worldwide), they represent an obvious welfare concern. There is also an economic impact due to labor time for treatment, medication, and premature culling of sows. While multiple factors contribute to ulcer development, maintaining optimum body condition in sows appears to be a key factor in prevention. This review summarizes the literature on sow shoulder ulcers, including the causes, prevention, and treatment. Regular monitoring of lesions is recommended, as this will help to identify individual farm causes and prevention measures. While much is known about shoulder ulcers, we conclude that there are significant gaps in the scientific literature regarding the mechanisms of development and healing, pain caused, and effective means for treatment and prevention.