LSD (LUMPY SKIN DISEASE )

Lumpy Skin Disease – An Overview

October 18, 2022

685

Lumpy Skin Disease – An Overview

Dr. Abadhut Dey¹, Dr. Dipanjan Jana²

¹Subject Matter Specialist (Animal Husbandry), Ramkrishna Ashram Krishi Vigyan Kendra, Nimpith Ashram-743338, Nimpith, South 24 Parganas

²MVSc, Dept. of Livestock Products Technology, West Bengal University of Animal and Fishery Sciences, Kolkata-700037

Email – deyabadhut@gmail.com

Abstract

Lumpy skin disease is an infectious, trans-boundary, eruptive, occasionally fatal disease of cattle and buffalo, which often occurs in epizootic form. The mode of transmission of the disease has not been clearly established. Contact infections do not readily occur and the evidence from the epizootiology strongly suggests that insect vectors are involved. The possible reason of expansion of the disease is by the biting insects like hypersensitivity to bits, mosquitoes, flies and some possibly ticks. The disease is characterized by fever (106℉), anorexia, pneumonia, depression and the eruption of nodules (2-4cm in a diameter) in the skin, which may cover the whole of the animal’s body and also reduces milk yield as well as abortion in pregnant animals. Nodules (enlarged superficial lymph nodes) are often found in the mouth and upper respiratory tract. These nodular lesions cause permanent damage to the hides. The severity of this disease varies considerably between breeds and strains of cattle. The prevention of disease quarantine like movement control of the animals, management strategies of the disease and sheep pox vaccines have been used for the animals against LSD. Before vaccination campaigns took their fully effect, the disease continued spreading from region to region and area to area, mainly showing seasonal patterns despite implementing control and eradication measures. The disease is capable of appearing several hundred miles away from focal outbreak sites within a short period of time.

Keywords: lumpy skin disease, vectors, capripoxvirus, transmission, goat pox, sheep pox, vaccines, outbreak, trans-boundary disease, skin lesions, hide.

Introduction:

The LSDV, a member of the poxviridae family of the genus Capripox virus, is the culprit behind Lumpy Skin Disease. The “Neethling Virus” is another name LSD virus. The livestock industry has suffered a significant economic loss as a result of this disease, which has affected both the production of milk and leather. It is a very contagious illness that is spread by blood feeding vectors (by biting flies, fleas, mosquitoes, and other insects) as well as tainted food and drink and close contact with animals. LSD was firstly seen in Zambia as an epidemic in 1929. LSD has been confined to sub-Saharan Africa, until it recently appeared in epizootic form in Egypt and in Israel. More recently, in 2019, in Bangladesh, and is currently in India, this disease has spread havoc and killing thousands in a number of these regions, including Gujarat, Maharashtra, Punjab, Rajasthan, and Uttar Pradesh, Madhya Pradesh etc., the virus is extending its roots. The virus quickly accumulated a large number of fatalities and wreaked devastation in India. This is an economically important viral disease of cattle and buffalo causes chronic debility in the infected animal, severe or permanent damage of hides due to skin lesions, severe emaciation, remarkable decreased of milk production and in some cases death of the infected animal. The Indian government has established necessary policies and also banned bullock cart races, livestock fairs, and inter-state animal transportation in order to reduce animal mortality or to stop its further spread of disease.

History

Lumpy skin disease was first seen as an epidemic in Zambia in 1929. Additional cases occurred between 1943 and 1945 in Botswana, Zimbabwe, and the Republic of South Africa. Approximately, 8 million cattle were affected in a panzootic infection in South Africa in 1949, causing enormous economic losses. LSD spread throughout Africa between the 1950s and 1980s, affecting cattle in Kenya, Sudan, Tanzania, Somalia, and Cameroon. In 1989 there was an LSD outbreak in Israel. Since 2012, the disease has expansion rapidly throughout the Balkan region, Southern Caucasus, Middle Eastern and parts of the Russian Federation. LSD was first reported to the Bangladesh livestock department in July 2019. Eventually 500,000 head were estimated to have been infected in this outbreak. In 2022 a lumpy skin disease outbreak in Pakistan killed over 7000 cattle, as reported. In India between July-September 2022 the lumpy skin disease outbreak in India resulted in the death of over 80,000 cattle. The state of Rajasthan has seen a majority of the deaths.

Classification & Position of Lumpy Skin Disease Virus

Lumpy skin disease virus (LSDV) is double-stranded DNA virus. It is a member of the capripoxvirus genus of Poxviridae family. Capripoxviruses (CaPVs) represent one of eight genera within the Chordopoxvirus (ChPV) subfamily. This virus is one of the closely related to three species within of the genus capripoxvirus and other two species are sheep pox virus, and goat pox virus. CaPV infections are usually host specific within specific geographic region even though they are serologically apart from one another.

Kingdom: Bamfordvirae

Phylum: Nucleocytoviricota

Class: Pokkesviricetes

Order: Chitovirales

Family: Poxviridae

Genus: Capripoxvirus

Species: Lumpy skin disease virus

Epidemiology

Lumpy skin disease virus mainly affects cattle and zebus, but has also been seen in water buffaloes, giraffes, and impalas. Fine-skinned Bos taurus cattle breeds such as Holstein-Friesian (HF) and Jersey are the most susceptible to the disease. Thick-skinned Bos indicus breeds show less susceptible to the disease.This is probably due to the decreased susceptibility to ecto-parasites that Bos indicus breeds exhibit relative to Bos aurus breeds. Cows at peak lactation and young calves show more severe clinical signs, but all age-groups are susceptible to the LSD virus infection.

LSD Transmission

Outbreaks of this virus are associated with high temperature and high humidity. It is usually more prevalent during the wet summer and autumn season, however, outbreaks can also occur during the dry season.
Still now, information about LSD virus transmission is wanting.
According to various experimental works has shown that Blood feeding arthropods such as fleas, ticks, mosquitos and flies act as mechanical vectors to spread the disease. A single species vector has not been identified till now. According to several laboratory researches, the virus has been isolated from Glossina, Stomoxys, Tabanidae, and Culicoides The particular role of each of these insects in the transmission of LSDV continues to be evaluated.
Outbreaks of lumpy skin disease tend to be sporadic since they are dependent upon animal movements, immune status and wind and rainfall patterns, which affect the vector populations.
The virus can be transmitted through blood, lacrimal secretions, semen, nasal discharge and saliva. The disease can also be transmitted through infected milk to suckling calves.

Cardinal Signs and Symptoms of LSD

The first symptom displayed by an infected animal is fever (106℉) and last for up to a week.
Additional symptoms include anorexia, emaciation, nasal discharge, swollen lymph nodes, respiratory distress, conjunctivitis, poor development, ocular discharge, hyper salivation, oedema of limbs, brisket region and limbs that causes animal to be lame etc.
Large circumscribed nodules appearing all over the body are the main pathgnomic lesion for this disease. The nodular lesions involve in epidermis layer, dermis layer, and sub-cutis and frequently have considerable oedema. These are about 1-5 cm in size. These oedematous growths are intradermal, slightly elevated, intact and very painful to animal. It infects also the gastrointestinal, respiratory and genital tracts. These lesions are usually recovery of the lesions within 2-4 weeks but some may remain for years.
Additionally, milk production declines and the quality of the hide degrade because of nodules, both of which result in financial losses.
Abortions in various animals have also been documented.
Bulls may become permanently or temporarily unfertile.
Death of cattle in many complicated cases. Mortality may be 5%-10% of animal.

LSD affected Cow

Differential Diagnosis :

Histo-pathological Findings
Eelectron Microscopy
Polymerase Chain Reaction
Serological Techniques – Virus neutralization, Western Blot, ELISA test
Virus Identification or Isolation
Restriction Fragment Length Polymorphism (RFLP) is also used to differentiate between virulent LSDV strain and vaccine strain.
The clinical diagnosis of LSD is confirmed by laboratory testing of blood samples and tissue samples from the skin lesions.

Treatment:

Despite the fact that there is no conclusive permanent treatment method for this virus-based disease, animals can still is saved by receiving the appropriate veterinary care, such as painkillers, fluids etc. Most of the treatment based on symptomatic approach. Success is based on the immunity level of the individual cattle.
Use of antibiotics to prevent secondary bacterial infections.
Affected animals should keep at isolation zone or quarantine zone and providing clean, disinfected water and good quality food and maintain possible biosecurity measures.
Administration of povidone iodine (Betadine 5% or 10% w/v) ointment to cure wounds.
Use of fly repellents to keep flies away and to prevent the growth of maggot wounds are all recommended.

Vaccination:

Currently, live ɑttenuɑted vaccines, based on LSDV strain, sheep pox virus (SPPV), or ǥoɑt pox virus (GTPV) make up the majority of commercially ɑvɑilɑble LSD vaccines.
Indian Council of Agricultural Researchlabs have undertaken creation of an indigenous vaccine. A goat pox vaccine is being used; 15 million doses had been administered by September 2022.
The infected area are identified so that precautionary plans are carried out in a specific area and ring vaccination carried out in villages up to 5 km around the affected area. However, affected animals should not be vaccinated.
The staff and vaccinators should be trained for vaccination drive including storage and preparation of vaccine, dosing and injection and identification of animal.
The Food and Agriculture Organization(FAO) also recommended for mass vaccination.

Preventive & Control measures

Immediate isolation or quarantine of diseased animal from the healthy ones.
Control of vector population (ticks, flies, mosquitoes, fleas, midges) in the premises and the animal body should be carried out using insecticide, flies repellents and other chemical agents.
Symptomatic treatment of affected animals may be carried out with all precautions and biosecurity measures. Good quality, liquid, soft feed and fodder is must provide.
Prevention of bathing the affected cattle reduces the severity and spread of the disease.
Clinical surveillance against LSD in affected places and around surrounding villages should be intensified.
The animals should be kept separately till complete recovery of the affected animals, if reared together.
The affected cattle not exposed to direct hot sunlight.
Disinfection of premises at regular intervals.
Ecto-parasiticide should also be applied to healthy animals on the infected and on surrounding farms.
The persons dealing with the infected animal should wear gloves and face masks and carry out hygienic and disinfection measures at all times.
Veterinary care should be taken to report any unusual sickness of other animals to the nearest veterinary Hospital.
Farms with affected animals should be visited regularly by field veterinarians until all the cases are recovered. The veterinary staff should take all precautionary hygiene measures to avoid the further spread of disease to other farms/households.
Carcass should be disposed of by deep burial method observing all hygienic measures.
Livestock markets located within 10 km radius of the epicentre of infection should be closed.
Trade of live cattle, participation in fairs, and shows should be banned immediately upon confirmation of the disease in the affected areas.
Semen from LSD-affected animals should not be collected and processed for production and distribution.
Waste disposal including feed, fodder and dead animal to be followed as per scientific method with marking and displayed safety guidelines Insecticides spray and fogging to be undertaken in the animal sheds, common grazing area, veterinary hospital and dispensaries, animal gathering spots and animal movement tracks to control vectors like mosquito, flies, ticks, fleas etc.
Infected feed, fodder and bedding material should not be used and disposed scientifically

Control Strategies:

The control of insects is crucial since the disease is arthropod carried, meaning that it spreads by bug bites. It is accomplished by smouldering manure with neem leaves in the evening.
For control of flies, use of ecto-parasiticide with each ml contains Deltamethrin (12.5 mg) liquid 2ml in one litre of water in the body of the cattle.
Same liquid 5ml in one litre of water, use as a spray for cattle shed follow the company recommendations and consult the Veterinary Doctor before application.
Keeping the sick animals apart.
The ‘Goat Pox Vaccine’ is being used in impacted States to stop the spread of LSD because immunisation has produced positive outcomes, according to the Union Ministry of Fisheries, Animal Husbandry and Dairy.
The likelihood of infection will also be reduced by wearing gloves and a face mask during milking.
Mass awareness campaign to be taken up to make the public aware of the disease and report to the veterinary authority immediately when suspected cases are detected. This will help in prevention and control of LSD.

Economic Impact:

LSD has high economic importance, it impacts our three major livestock based business or economy. One major impact is a reduction in milk production, which causes the dairy business to suffer greatly, and another is the presence of nodules or lesions on skin, which lowers the quality and market value of hide tremendously and causes losses for the leather industry. Meat industry also hampered badly.

Conclusion:

Although the fact that there is no permanent treatment for this virus-based disease, animals can still be saved by receiving the appropriate veterinary care and treatment. Animals are immunized using the vaccine for goat pox. Additionally controlling fleas, lice, flies and mosquitoes by using fly repellent materials or using ecto-parasiticide or burning neem leaves along with the animal waste, as well as routinely cleaning the animal barns. While milking the animals, farmers should wear gloves and a mask to prevent any type of contamination. Farmers and customers shouldn’t accept the market myths that milk from diseased animals shouldn’t be drank; you may do so without risk if you pasteurize the milk first. The fact that this disease is not a zoonotic illness is crucial. When an animal dies, the carcass should be properly disposed of scientifically, and the area should be carefully cleaned and disinfected. LSD can be minimizing by following preventive and control measures and veterinary care or supportive treatments.

References: