Lumpy Skin Disease in Cattle
An Emerging threat in Kashmir Region
The disease is caused by lumpy
skin disease virus (LSDV) which is
antigenically related to goat pox and sheep pox virus
DR. NUZHAT HASSAN
DR. SHAHNAZ BASHIR
Lumpy skin disease (LSD), the infectious and contagious viral disease of cattle is spreading throughout India. However, recent outbreaks in India are very extensive and case fatality rates are even higher. First time the Lumpy skin disease in cattle was detected from the African country Zambia in 1929 and until 1980 the disease was limited to the sub-Saharan African countries. Then it started to spread across the borders because of global trade of livestock and their products. Currently this disease is endemic in Africa, parts of the Middle East and Turkey, however recent outbreaks were reported as north as Russia, Armenia, Azerbaijan, Turkey and southern and eastern Europe. In India the disease was first detected and identified from Odisha in 2019. Initially it was restricted to eastern parts of the country, now the disease is spreading at an alarming rate in cattle; outbreaks are even reported from as far as Andaman and Nicobar regions of the country.
The disease is caused by lumpy skin disease virus (LSDV) which is antigenically related to goat pox and sheep pox virus. This is primarily the disease of cattle but can affect the buffaloes with milder symptoms. Cattle of all age groups and breeds are equally susceptible to this disease. Till now, there is no evidence that the virus is zoonotic and does not cause disease in humans. The virus is present in almost all the secretions (saliva, nasal secretions, milk, blood, semen, lachrymal) of the infected animal and can survive up to 6-months under favourable conditions. The spread of the virus occurs directly from infected to healthy animal via contaminated drinking water and feedings. The mechanical transmission by multiple arthropod vectors (house flies, mosquitoes, hard tics, horse flies, biting midges etc.) plays a very important role in disease spread especially during the humid, wet and waterlogged environmental conditions. The disease can be distinguished from other disease forms by the typical clinical features manifested.
The incubation period is around 4-14 days with the onset of high fever (40-410C), excessive salivation, lacrimation, nasal discharge, swollen lymph nodes and the presence of pathognomonic nodules on any part of body especially skin of head, neck, limbs, udder and nose, and mucosa especially the oropharynx, respiratory tract and gut mucosa. Sudden and sharp drop in milk production in cattle. These nodules have a typical shape like round, firm, raised usually separated from the adjacent healthy tissue by a narrow haemorrhagic band. The nodules may ulcerate or may get separated, leaving a deep hole inside the skin which become seats for secondary bacterial or fungal infection. Mucosal lesions are initially round but quickly ulcerate. Swelling and edema can develop on lower limbs, brisket and udder. The secondary bacterial involvement can lead to mastitis that can be devastating in case of high yielding dairy animal. Most of the affected animals recover slowly and it may take months even. The production potential of the animals gets severely reduced and other indirect loses are due to the damaged hide/carcasses, mastitis, abortions, infertility, treatment and management costs. The disease can be diagnosed in the field conditions by the typical clinical picture of the infected animal so as to act promptly against it. For confirmatory diagnosis, different samples (blood in early stage, nodular tissue) can be sent to the designated laboratories for isolation and identification of the virus. Treatment is non-specific and more oriented towards the resolution of clinical signs.
Some of the measures to prevent the disease from spreading are:
• The immediate preventive step is to isolate the sick animal as early as possible. Strict control measures on movement of the cattle need to be taken across the borders of the valley and from within the districts in case of outbreak reports.
• Vector control measures need to be taken as vectors play important role in disease transmission. Use of fly and mosquito repellents to minimize the transmission. Ecto-parasiticides especially acaricides can be recommended by the veterinary doctors.
• In case of death of the animal, deep burial (>2 meter) of the carcass is recommended.
• Thorough cleaning and disinfection of anything that comes in contact with the infected animal i.e., personnel, premises, equipments, environment even the transportation medium.
• The healthy and unaffected animals must be vaccinated. Goat pox vaccine can be given to bovines as there is strong cross protective immunity between the virus species. Prophylactic vaccination is the promising tool to prevent and stop the disease spread across the herds.
The purchase and transport of animals should be banned from other states for a recommended period as vaccination drive has been initiated against LSD in the country particularly in the affected states. Since, it takes around 28 days (>3 weeks) to develop full protection from the vaccine, therefore, it is highly important to have the stand-by period of 28 days before certifying the cattle as LSD vaccinated. Indigenous attenuated homologous LSDV Vaccine developed in 2019 by Indian Council of Agricultural Research (ICAR) and National Research Centre for Equines (NRCE) is the first vaccine that has now been approved for manufacturing and marketing against LSD in animals known as LUMPY-Pro Vac Ind.
(Dr. Nuzhat Hassan is Assistant
Professor, Division of Veterinary Epidemiology and Preventive Medicine, FVSc& AH, SKUAST-K) & Dr. Shahnaz Bashir is Assistant Professor, Division of Veterinary Epidemiology and Preventive Medicine, FVSc & AH, SKUAST-K)