Lumpy skin disease, as the name specifies, causes development of lumps on the skin.It is an infectious and contagious viral disease of bovines (specifically of cattle and water buffalo) characterised by formation of eruptive nodules on skin and different parts of body. Secondary bacterial infection complicates the condition.
Traditionally and originally, lumpy skin disease belongs to southern and eastern Africa. Most recent, outbreaks of lumpy skin disease were reported from arid region of Thar desert, the Western Rajasthan, India (including districts mainly Jaisalmer, Barmer, Bikaner and surrounding area) during peak summer of 2022, when Tmax = 48°C and Tmin = 20°C are being reported
Etiology and Epidemiology
Main etiological agent is lumpy skin disease virus (LSDV), a member of the Capripoxvirus genus and belongs to Poxviridae family. Its occurrence is both epidemically or sporadically. It is not uncommon that, new foci of this disease appear in regions totally isolated from the initial outbreak. Disease exhibits highest incidences during hot and humid summer, but in some circumstances may occur in winter. It is most prevalent along water courses and on low ground. Role of biting insects as mechanical vectors in spread of disease is not clear.
- This disease has potential to establish and spread in a vast range of environmental and productions systems throughout the world.
- The transmission is not completely known.
- The important routes are movement of infected animals, by fomites which carry contaminate secretions and/or body fluids or tissues, directly from animal to animal and mechanical transmission by arthropod vectors such as mosquitoes, ticks and biting flies.
- Incubation period is 4 to 14 days.
Affected animal shows following signs and symptoms:
- Nasal discharge
- Swelling of the limbs, brisket and genitals
- Development of nodules which are well circumscribed, round, raised, firm, and painful and may involve any part of the body. Nodules mainly develop on the skin around the head, neck, genitals and limbs and may up to 50 mm in diameter. Scabs develop in the centre of the nodules after which scabs fall off, leaving large holes that may become infected. A firm, creamy-gray or yellow mass of tissue found in skin nodules. Regional lymph nodes are swollen, and oedema develops in the udder, brisket, and legs. It may involve the entire cutis and the mucosa of the gastrointestinal, respiratory, and genital tracts. Nodules may also develop on the muzzle and within the nasal and buccal mucous membranes. The nodules either regress, or necrosis of the skin results in hard, raised areas (“sit-fasts”) clearly separated from the surrounding skin. These areas slough off to leave ulcers, which heal and scar. Secondary infection sometime occurs and causes extensive suppuration and sloughing; as a result, the animal may become extremely emaciated.
- Morbidity is 4%–49%;
- Mortality is generally low.
- Main economic loss is reduced milk yield, loss of condition, and rejection or reduced value of the hide.
- Virus isolation
Treatment and Prevention
- Isolate the animal from the herd
- There is no treatment for the virus, so prevention by vaccination is the most effective means of control. Attenuated virus vaccines may help control spread
- Supportive and symptomatic treatment like non-steroidal anti-inflammatory drugs (NSAIDs), multivitamins, mineral mixtures and fluid therapy.
- Symptomatic treatment in case of secondary infections with antibiotics (topical +/- injectable).
- Better management and care.