Clinical and Pathological Features of the Porcine Ulcerative Dermatitis Syndrome (PUDS)

Abstract

The nomenclature of ulcerative dermatitis as used in literature is somehow confusing because on the one hand this skin disorder is associated with bacterial growth and on the other hand it is a synonym for a chronic sporadic disease of adult sows with unknown aetiology. Thus, we propose the terminus 'Porcine Ulcerative Dermatitis Syndrome (PUDS)' for the latter to distinguish between these two disease complexes. This syndrome could be identified by clinical and pathological examinations in six sows, that were submitted to the clinic. Epidermal ulcers could be found nearly all over the body, but teats were always spared. Haematological examination showed a slight anaemia but physiological leucocyte counts. However, lymphopenia (x = 44.8%), granulocytosis (x = 42.0%) and an increased number of monocytes (x = 13.1%) could be found. Histologically, a lymphoplasmacytic and granulohistiocytic infiltration in the corium was most prominent. In some cases, a moderate leucocytoclastic vasculitis and perivasculitis could be seen at the dermo-epidermal border. Additionally, a multifocal interstitial nephritis with lymphoplasmacytic infiltration was a prominent feature in all animals. Participation of an immune complex associated disorder can be assumed when regarding histological findings as skin lesions in combination with glomerulonephritis are a common feature of such diseases. Also, IgG levels were elevated two- to fourfold in all affected sows when compared with healthy control pigs. This supports the hypothesis that not only T cells, as shown previously, but also the humoral branch of the immune system is involved in the aetiology of PUDS.

Chronological clinical and pathological documentation of porcine ulcerative dermatitis

“…Porcine ulcerative dermatitis syndrome has been proposed to be a porcine homologue of vesicular cutaneous lupus erythematosus (VCLE) of Shetland sheep dogs and rough collies . Although the histopathological changes may be comparable, vesicles were not observed in this sow and others, and PUDS clearly is not associated with ultraviolet (UV) light as was suggested for canine VCLE .…”

“…Usually only a single sow within a herd is affected. PUDS occurs primarily in pluriparous sows during gestation, sometimes extending into lactation and even past weaning . At present the pathogenesis of PUDS is unknown .…”

“…PUDS occurs primarily in pluriparous sows during gestation, sometimes extending into lactation and even past weaning . At present the pathogenesis of PUDS is unknown . Histopathological reports describe different disease stages and have proposed different pathogenic mechanisms .…”

“…1 Clinical signs include coalescing ulcerations of the skin around the teats which may extend to the lateral aspects of the limbs, ears, lateral thorax, perineum and rarely to the dorsum. 1 Usually only a single sow within a herd is affected. PUDS occurs primarily in pluriparous sows during gestation, sometimes extending into lactation and even past weaning.…”

“…1 At present the pathogenesis of PUDS is unknown. 1 Histopathological reports describe different disease stages and have proposed different pathogenic mechanisms. 1,2 Resemblance to vesicular cutaneous lupus erythematosus in the rough collie and Shetland sheep dog has been suggested.…”