| Résumé : |
A survey of 5250 goats and 4220 sheep in the Sudan for sarcoptic mange revealed an incidence of 5,5 % (290) in the former and 5,2 % (221) in the latter species, respectively.
Severe and localised or generalised lesions were seen in the infested animals. Skin scrapings from infested animals revealed numerous specimens of sarcoptes scabiei, showing that the animals were heavily infested.
Severe histopathological changes were seen in skin sections. These changes mainly comprised : hyperkeratosis, acanthosis ans scab formation, beneath which numerous mites were seen. Severe cellular infiltration, micro-abscessation, degenerative and necrotic changes and marked proliferation of connective tissue also occured.
Infested skins were green graded as "rejects" and the prepared crust leather was graded as "rejects" or "double rejects". Infested skins were difficult to finish into crust leather. The disease caused a marked reduction in the aesthetic appeal and cutting area of the leather. The crust leather prepared from infected skins was unsightly, hard, and fibrosed, with many tunnellings. The grain surface was coarse, rough and the fibres were loose and had a fluffy appearance. In severely infested areas, numerous holes were seen and, in some cases, the leather was completely damaged.
Leather sections from infested areas showed great distortion and disintegration of the fibres with large areas of micro-abscessation. Towards the grain surface, the fibres along the tunnels of the mite were eaten away, became thin, loose and had a fluffy appearance beneath which many empty spaces and areas of fibrosis were seen.
The disease caused a marked reduction in the tensile strength and apparent density of crust leather. In severely infested animals,the leather specimens were cut before the machine could even give a reading, showing complete loss of durability. The disease caused a false increase in the mean thickness and volume but brought about a marked reduction in the weight of the infested specimens.
Skins so affected were completelyrejected or fetched very low prices resulting in serious economic losses.
Goats were experimentally infested with sarcoptes scabiei mites. The results obtained from the clinical picture of the lesions produced, the grading of skins, the examination of histological and leather sections and physical testing of the crust leather produced, confirmed the results obtained from the survey. Treatment of the experimental lesions led to improvement of the quality of the leather eventually produced, showing that recovery from the damage could be obtained, providing that infested animals are (a) treated in the early stages of the disease and (b) ample time is given before the animals are slaughtered, in order to allow for proper restoration of the skin. |
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Sarcoptic mange in goats and sheep : studies on the defects and economic losses resulting from damage caused by the disease on crust leather in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 72 (Année 1988)
