TREATMENT & CONTROL OF LUMPY SKIN DISEASE IN ANIMALS
Lumpy Skin Disease (LSD) has been reported in various Indian states like Assam, Odisha, Maharashtra, Kerala, Karnataka, Chhattisgarh, Madhya Pradesh, etc. Let us study LSD in detail, its transmission, symptoms, treatment, prevention, etc.
Lumpy Skin Disease (LSD) is fast spreading in various states in India creating panic among dairy farmers. It has been infecting cattle and bovine animals.
It is said that the virus is not zoonotic and does not infect humans through the consumption of milk or meat. Basically, it affects the cow and buffalo, and maybe the infection in the latter has been found to be minimal.
Background
As per some sources in 1929, LSD was first described in Zambia. Over the next 85 years, it spread throughout the majority of Africa and into the Middle East. In Greece in Europe, the virus entered in 2015 and also in Caucasus and Russia. Further, the virus spread in 2016 into the east in Balkans, north towards Moscow, and west into Kazakhstan. LSD was first reported in India in August 2019 from Mayurbhanj, Odisha.
More than 3,000 cattle have died in Rajasthan and Gujarat due to the Lumpy Skin Disease. In Rajasthan, the viral infection was confirmed across nine districts where around 2,500 cattle deaths have been reported in total from Barmer, Jalore, Jodhpur, Bikaner, Pali, Ganganagar, Nagaur, Siorhi and Jaisalmer. Last month, Gujarat’s Agriculture Minister said Lumpy Skin Disease claimed lives of 977 cattle in the state. The virus spread in 14 districts, including all districts of Saurashtra region, Kutch and now Banaskantha. Both Rajasthan and Gujarat have sounded high alert in connection to the Lumpy Skin Disease.
What is Lumpy Skin Disease (LSD)?
It is a viral disease that is caused by lumpy skin disease virus (LSDV), a member of the Capripoxvirus genus of the Poxviridae family.
Or we can say that it is caused by infection of cattle or water buffalo with the poxvirus Lumpy skin disease virus (LSDV). The virus is one of the three closely related species within the genus capripoxvirus and the other two species are Sheeppox virus and Goatpox virus.
Lumpy Skin Disease, also called LSD, is caused by lumpy skin disease virus (LSDV), a virus from the family Poxviridae, genus Capripoxvirus. Sheeppox virus and goatpox virus are the two other virus species in this genus, according to the World Organisation for Animal Health. There is no vaccination available for the disease which is being treated based on symptoms.
Can humans get infected with Lumpy Skin Disease
LSDV is highly host-specific and causes disease only in cattle (Bos indicus and B. taurus) and water buffalo (Bubalus bubalis). A study in Ethiopia showed evidence of differential breed susceptibility to LSD, with Holstein Friesian or crossbred cattle exhibiting higher morbidity and mortality due to LSD when compared with local zebu cattle. LSDV is not zoonotic, so humans cannot get affected by the disease.
Lumpy Skin Disease: Symptoms and how it spreads
- The Lumpy Skin Disease spreads through bloodsucking insects, certain species of flies and through contaminated food and water.
- It causes acute fever, discharge from the eyes and nose, salivation, soft blister-like nodules all over the body, marked reduction in milk yield and difficulty in eating.
- The mortality rate for the contagion is 1.5 per cent.
How is LSD transmitted?
Still, information on the transmission of this virus is lacking. Several experimental works has shown that direct transmission from an infected to a naïve animal is very inefficient. Some evidence supports that transmission of the virus is through arthropods like insects or ticks and are termed as virus “vectors”. However, it is unclear which vector species are involved in transmission.
As per some researchers, it spreads through mosquitoes, flies, and ticks. Sometimes through saliva and contaminated water and food. The factors determining which cattle develop mild and which develop a severe disease are unknown. One of the significant factors for spreading LSD over large distances can be the movement of infected cattle.
By laboratory diagnosis, the disease can be confirmed with tests available to detect the DNA of the virus or antibodies.
What are the symptoms of LSD?
All over the body of the animal, the disease appears as the nodules of two to five-centimeter diameter mainly around the head, neck, limbs, mammary gland of female cattle, and genitals. And the lumps open up like large and deep wounds.
Some other clinical signs are general malaise, ocular and nasal discharge, fever, and a sudden decrease in milk production.
As per the Food and Agricultural Organisation (FAO), the mortality rate is less than 10%.
How is LSD prevented?
Lumpy Skin Disease, control, and prevention depend upon four tactics namely movement control (quarantine), vaccination, slaughter campaigns, and management strategies. Specific control plans vary between countries so advice should be taken properly from the relevant authorities and veterinarians.
No doubt the most effective way to control is the vaccination and a live homologous vaccine consisting of a Neethling-like strain of LSDV is recommended.
What is the treatment of LSD?
Treatment for this virus is still not there but the most effective means of control is prevention by vaccination. Also, secondary infections in the skin may be treated with Non-Steroidal Anti-Inflammatories (NSAIDs) and also antibiotics when appropriate.
So now we come to know that the Lumpy Skin Disease virus causes severe disease in cattle which is characterised by nodules in the skin. Its transmission may occur through insect vectors and vaccination is the most preventive way to control it. It causes substantial losses in affected herds with significant economic consequences. The disease will also have a devastating impact on the country, where most dairy farmers are either landless or marginal landholders and milk is among the cheapest sources of protein.
Clinical signs
Clinically, disease may range between subclinical disease to severe illness or death.
Initial clinical signs may include fever (40-41.5 0C), depression, anorexia, and reluctance to move. Rhinitis, conjunctivitis and excess salivation may also be apparent.
Cattle may develop large, firm nodules (up to 5 cm in diameter) in the skin. These can be found over the entire animal, but are found particularly on the head, neck, udder, scrotum and perineum. The nodules may become necrotic and ulcerate, leading to an increased risk of secondary bacterial infections and flystrike. In severe cases, the nodules can fall away leaving full-skin thickness holes in the animals hide.
Affected bulls may not work due to painful lesions on their prepuce, and cows may abort or become anestrus. Live neonates or aborted fetuses from infected cows may also present with skin lesions.
In severely affected animals, lesions can also develop in the respiratory and gastrointestinal tract. Pneumonia is a common, and often fatal, complication.
Bos taurus cattle are generally more susceptible than Bos indicus cattle. Jersey, Guernsey, Friesian and Ayrshire breeds are particularly susceptible.
Morbidity rates vary greatly, ranging between 1-95%. Mortality rates are usually 1-5%, but have been reported as high as 75%.
Disease transmission
Lumpy skin disease virus is spread primarily by biting insects such as flies and mosquitoes, and possibly ticks. It can also be transmitted by fomites, and in some cases, from animal to animal.
The virus is present in high concentrations in the skin nodules and scabs on affected animals, and can be isolated from blood, saliva, ocular and nasal discharges and semen.
Virus can be found in blood for up to 21 days post-infection. Shedding in semen may continue for at least 42 days post-infection.
Lumpy Skin Disease is not Zoonotic
The virus is highly host specific and does not cause disease in humans.
There is no risk from consuming beef or dairy products.
Differential diagnoses
Differential diagnoses include:
urticaria
pseudo lumpy skin disease (bovineherpes mammalitis; herpesvirus 2)
bovine papular stomatitis (parapoxvirus)
dermatophytosis (Trichophyton spp., Microsporum spp.)
pseudo cowpox (parapoxvirus)
vaccinia virus and cowpox virus (orthopoxviruses)
streptothricosis (Dermatophilus congolensis)
demodicosis (Demodex bovis)
insect or tick bites
onchocercosis (Onchocerca spp.)
besnoitiosis (Besnotia besnoiti)
cutaneous actinobacillosis (Actinobacillus lignieresi)
rinderpest
Hypoderma bovis infection
photosensitization
skin tuberculosis.
Sample collection
Diagnosis of lumpy skin disease is based primarily on detection of the virus in lesions. Detection of antibody in serum may also aid diagnosis.
Specimens that should be collected from live animals include:
- blood (from animals with fever)
- serum
- nodular fluid
- skin biopsies of suggestive lesions
- scabs, and
- skin scrapings from lesions.
At necropsy, a range of samples, both fresh and fixed, should be taken from skin lesions, lesions in the respiratory and gastrointestinal tracts, and other internal organs.
By- Dr.Nirbhay Kumar Singh
Assistant Professor
Dept. of Veterinary Anatomy
Bihar Veterinary College
Patna
