lumpy skin disease in cattle Effect

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lumpy skin disease in cattle Effect

Lumpy skin disease (LSD) is an economically important disease of cattle and can produce a chronic debility in infected cattle comparable to that caused by foot-and-mouth disease (FMD). Mortality rates as high as 40 percent or more have been encountered but they are usually lower. Severe and permanent damage to hides results from the skin lesions. Lesions in the mouth, pharynx and respiratory tract commonly occur, resulting in a rapid deterioration in condition and sometimes severe emaciation, which can persist for months. Serious economic losses can follow outbreaks that have a high morbidity.
There is no specific antiviral treatment available for LSD-infected cattle. Two vaccines, however, Neethling and Kenya sheep and goat pox virus, have been used widely in Africa with success.

History of lumpy skin disease

The clinical syndrome of lumpy skin disease (LSD) was first described in Zambia (formerly Northern Rhodesia) in 1929. Initially, it was considered to be the result either of poisoning or a hypersensitivity to insect bites. Between 1943 and 1945, cases occurred in Botswana (Bechuanaland), Zimbabwe (Southern Rhodesia) and the Republic of South Africa. The infectious nature of the disease was recognized at this time. A panzootic in South Africa, which lasted until 1949, affected some eight million cattle and consequently incurred enormous economic losses (Thomas and Mare, 1945; von Backstrom, 1945; Diesel, 1949).Clinical disease
LSD is an acute infectious disease of cattle of all ages. There have been five instances of clinical cases of LSD in Bubalus bubalis, the Asian water buffalo (All et al., 1990). No other domestic ruminant species becomes infected naturally during field outbreaks. There can be a pyrexia of 40 to 41.5 °C, with lachrymation, possible anorexia, some depression and a reluctance to move. Shortly afterwards, the characteristic skin lumps develop; they may cover the whole body or be restricted to the head, neck, perineum, udder, genitalia or limbs. The lesions first manifest themselves as round circumscribed areas of erect hair, measuring 5 to 50 mm in diameter. They are firm and slightly raised above the surrounding normal skin from which they are often separated by a narrow ring of haemorrhage. The lesions are of full skin thickness involving the epidermis, dermis and adjacent subcutis. The regional superficial lymph nodes are enlarged and oedematous.

There is an increase in nasal and oropharyngeal secretions, which may be associated with the development of lesions on the muzzle and in the mouth. They may be found anywhere in the oropharynx and the upper respiratory tract. Lesions can occur throughout the alimentary tract in the subcutis, muscle fascia and in the muscle itself. The lesions on the mucous epithelium are round (usually 4 to 40 mm in diameter) and have a ring shape where separation from the normal tissue has occurred. Necrosis follows quickly and the ulcers become infected. There are mucopurulent discharges from the mouth and nostrils, persistent dribbling....