Pathological evaluation of claw lesions in culled sows from a Greek herd

Abstract

Objectives: To characterize macroscopic claw lesions of culled sows, describe the histologic characteristics observed in the laminar corium and investigate their associations with lesion severity, and compare the morphometric characteristics of horn tubules among claws according to lesion severity. Materials and methods: One front and the opposite rear foot from 74 culled sows of one herd were examined for lesions. From each claw, a tissue sample consisting of dermis and epidermis was examined histologically for changes suggesting laminitis. Slices from the lateral claws of the rear feet of 48 sows were examined morphometrically to evaluate the density and size of horn tubules. Results: The most frequent lesions were those located on the heel, wall, and white line, with 146 (49.3%), 94 (31.8%), and 81 (27.4%) affected claws, respectively, among the 296 examined. Lamellar hyperplasia was the most frequently recorded characteristic in the epidermis of 87 of 296 claws (29.4%) in 51 of the 74 examined sows (68.9%). The total lesion score of the claw was higher (P > .001) when lamellar hyperplasia was recorded than when no histologic change was recorded. The density of horn tubules was lowest (P = .018) and the size was largest (P > .001) among animals with severe wall lesions, compared to those without wall lesions. Implications: The histologic changes observed in the dermis and epidermis of the sows' claws have been described in cases of equine and bovine laminitis. Sow laminitis may frequently occur, causing production of low quality hoof horn.