Lumpy Skin Diseɑse: A Worldwide Serious Concern

Lumpy Skin Diseɑse: A Worldwide Serious Concern

By – Ankit Kaushik

BVSc & Ah 4^th Year

Topic – Lumpy skin diseɑse: A worldwide serious concern

Ph. No. – 8920634687

Email address – kaushikwankit@gmail.com

Heɑlth mɑnɑǥement deɑls wíth monítorínǥ the heɑlth stɑtus of ɑnímɑls on the fɑrm. Animɑl heɑlth depends on nutrítíon ɑnd the envíronment. Fɑrm ɑnímɑls ínfectíous díseɑses ɑre cɑused by dífferent mícro-orǥɑnísms such ɑs bɑcteríɑ, vírus, funǥí, protozoɑ, mycoplɑsmɑ, ɑnd pɑrɑsítes. Amonǥ ínfectíous díseɑses, the íncídence of Lumpy skín díseɑse (LSD) ín cɑttle ɑnd buffɑloes ís recently híǥher in many regions of India. LSD wɑs fírst tíme díscovered ín Zɑmbíɑ. The recent ǥeoǥrɑphíc spreɑd of lumpy skín díseɑse hɑs cɑused ínternɑtíonɑl concern.

Introductíon

Lumpy skín díseɑse (ɑlso known ɑs Pseudo-urtícɑríɑ or knopvelsíekte) ís ɑ contɑǥíous skín díseɑse. LSD ís ɑn enzootíc ínfectíous, eruptíve, ɑnd rɑrely fɑtɑl díseɑse thɑt cɑuses nodules on the skín of cɑttle. Cɑttle ɑnd wɑter buffɑlo ɑre the only ɑnímɑl specíes ɑffected wíth ɑ híǥh morbídíty rɑte but low mortɑlíty; ɑlthouǥh, cɑlves díe ɑt ɑ ǥreɑter rɑte. LSD leɑds to ɑ reductíon ín mílk ɑnd meɑt productíon, ɑbortíons ín femɑles, ɑnd mɑle ínfertílíty. Secondɑry bɑcteríɑl ínfectíon often ɑǥǥrɑvɑtes the condition

AETIOLOGY

• Lumpy skin disease (LSD) is associated with poxvirus, a Capri poxvirus. It has close antigenic relationship to sheep pox and goat pox viruses
• Capripox viruses are resistant to drying and able to survive freezing and thawing, but most are inactivated by temperatures above 60°C

Epídemíoloǥy

• Lumpy skin disease was first seen as an epidemic in Zambia in 1929.
• Since then, sporadic cases and outbreaks have been reported from all over the world
• Outbreaks of LSDV are associated with high rainfall and high levels of insect activity.
• Its incidence is highest in wet summer weather and early autumn, but the disease may also occur in winter.

 

Susceptíble ɑnímɑls: Cɑttle ɑnd wɑter buffɑloes ɑre mostly ǥet ínfected wíth LSD.

• Althouǥh ɑll ɑǥe ǥroups of ɑnímɑls ɑre susceptíble, younǥ cɑlves ɑre more sensítíve to LSD ɑnd cɑn ɑcquíre the typícɑl lesíon wíthín 24 to 48 hours.
• Durínǥ fíeld outbreɑks, no other domestíc rumínɑnt specíes become ínfected nɑturɑlly.
• In India the disease appeared in August 2019 as severe epidemic in Odisha
• Now the disease has again surfaced as severe epidemic since July 2022 in Gujrat, Rajasthan, Punjab and adjoining states

Transmission: – Blood sucking insects such as mosquitos, stable flies, biting midges and ticks act as mechanical vectors to spread the disease.

• A single species vector has not been identified. Instead, the virus has been isolated from Stomoxys, Biomyia fasciata, Tabanidae, Glossina, and Culicoides, Rhipicephalus, Musca spp., after feeding on cattle with lumpy skin disease.
• The virus is shed through nasal and lacrimal secretions, saliva, semen, and milk of infected animals.
• The disease can also be spread by fomites through such things as contaminated equipment and in some cases directly from animal to animal.
• The disease can also be transmitted through infected milk to suckling calves.

Sources of virus

• Skin nodules, scabs and crusts contain relatively high amounts of LSDV.
• Virus can be isolated from this material for up to 35 days and likely for longer.
• LSDV can be isolated from blood, saliva, ocular and nasal discharge, and semen.
• LSDV is found in the blood (viraemia) intermittently from approximately 7 to 21 days post-infection at lower levels than present in skin nodules
• Shedding in semen may be prolonged; LSDV has been isolated from the semen of an experimentally infected bull 42 days post-inoculation.
• There has been one reported of placental transmission of LSD.
• LSD does not cause chronic disease. It does not exhibit latency and recrudescence of disease does not occur.

Economic Importance

• Mortality is usually low (Although it can be 5-10%), but economic losses are high.
• There is reduced feed intake, a reduction in milk production, and Occurrence of secondary mastitis associated with lesions on the teats o reduced body condition, decreased fertility in bulls, abortions may occur

 

Pathogenesis

• Virus transmitted mechanically by biting insects
• Rapid leukocyte viraemia
• Keratinocytes,myocytes,fibrocytes and endothelial cells get damaged
• Vasculitis, thrombosis, infarction, oedema and infilteration of inflammatory cells
• Skin nodule formation

Clinical Findings

• Fever that may exceed 41 °C (105 °F)
• Marked reduction in milk yield in lactating cattle.
• Depression, anorexia and emaciation.
• Rhinitis, conjunctivitis and excessive salivation.
• Enlarged superficial lymph nodes
• Pregnant cows may abort and be in anoestrus for several months.
• Bulls may become permanently or temporarily infertile.
• Cutaneous nodules of 2–5 cm in diameter develop, particularly on the head, neck, limbs, udder, genitalia and perineum within 48 hours of onset of the febrile reaction.
• These nodules are circumscribed, firm, round and raised, and involve the skin, subcutaneous tissue and sometimes even the underlying muscles.
• Large nodules may become necrotic and eventually fibrotic and persist for several months (“sitfasts”); the scars may remain indefinitely.
• Small nodules may resolve spontaneously without consequences.
• Myiasis of the nodules may occur
• Vesicles, erosions and ulcers may develop in the mucous membranes of the mouth and alimentary tract and in the trachea and lungs.
• Limbs and other ventral parts of the body, such as the dewlap, brisket, scrotum and vulva, may be oedematous, causing the animal to be reluctant to move

Differential diagnosis

Severe LSD is highly characteristic, but milder forms can be confused with the following:

• Bovine herpes mammillitis (bovine herpesvirus 2) (sometimes known as pseudo-lumpy skin disease)
• Bovine papular stomatitis (Parapoxvirus)
• Pseudocowpox (Parapoxvirus)
• Vaccinia virus and Cowpox virus (Orthopoxviruses) – uncommon and not generalised infections
• Dermatophilosis
• Demodicosis
• Insect or tick bites
• Besnoitiosis
• Rinderpest
• Hypoderma bovis infection
• Photosensitisation
• Urticaria
• Cutaneous tuberculosis
• Onchocercosis

Laboratory diagnosis

Samples Identification of the agent by:

• Polymerase chain reaction (PCR) is the least expensive and quickest method for detection of LSDV.Skin nodules and scabs, saliva, nasal secretions, and blood are suitable samples for PCR detection of LSDV.
• Virus isolation (VI) followed by PCR to confirm the virus identity takes longer and is more expensive but has the advantage of demonstrating the presence of live virus in the sample.
• Electron microscopy can be used to identify the classic poxvirus virion but cannot differentiate to genus or species level.

Serological tests

It is not possible to distinguish the three viruses in the Capripoxvirus genus (Sheeppox virus, Goatpox virus and LSD) using serological techniques.

Virus neutralisation: this is currently the gold standard test for the detection of antibodies raised against capripoxviruses.

Western blot: highly sensitive and specific but expensive and difficult to perform.

Capripoxvirus antibody enzyme-linked immunosorbent assay: new commercial kits for detection of capripoxvirus antibodies are currently being developed and released on to the market.

Necropsy Findings

• Typical skin lesions
• Similar lesions are present in the mouth, pharynx, trachea, skeletal muscle, bronchi, and stomachs, and there may be accompanying pneumonia.
• The superficial lymph nodes are usually enlarged.
• Histopathology of lesions reveals a granulomatous reaction in the dermis and hypodermis, with Intracytoplasmic, eosinophilic inclusion bodies a variety of cells types in early stages.

Treɑtment

There ís no pɑrtículɑr ɑntívírɑl therɑpy ɑvɑílɑble for LSD-ínfected cɑttle.

1. LSD affected animals should be separated from healthy animals and shall be kept in strict isolation and monitoring under veterinary supervision.
2. Symptomatic treatment including the treatment of secondary infection (if any) shall be carried out during isolation of animal.
3. Based on the symptoms and clinical signs following is recommended:
4. a) Use of anti-inflammatory drugs (preferably non-steroids) to treat the inflammatory condition
5. b) Use of anti-histamine preparations/drugs to treat allergic conditions
6. c) Use of Paracetamol in case high fever is observed
7. d) In case of secondary bacterial infections like respiratory infections, skin infections antibiotics may also be used judiciously. The dose and duration of the antibiotics should be strictly adhered including advice to the owner to follow the withdrawal period for milk.
8. e) Parental/oral multivitaminsmay also be given.
9. Feeding of liquid feed/food, soft feed and fodder and succulent pasture is recommended
10. Use of Herbal Solutions

The under mentioned Herbal Animal Health Solutions also offers a supportive role in management of Lumpy Skin.

• Wound Healing and Fly Repellents- Available herbal spray, cream and gel promotes rapid wound repair in the skin nodules due to rapid collagenisation, have strong fly repellent action that prevent flies from sitting on the wounds and prevents maggot in wounds.

Preparations: Like Topicure Advance Spray Natural Remedies Skin Healer and Fly Repellent, Scavon skin spray, charmil skin spray, Himax cream, Skin heal and Tee burb Indian Herbs Oral skin healer may be used.

• Appetite and Digestive Tonics- Appetite stimulants restore the appetite, rumen functions and also prevent loss of body condition among animals

Preparations: Like Himalayan Battista 100gm Indian Herbs, Appetonic 50gm HDC and Ruchamax 15gm/300g may be used

• Immunomodulators and antioxidants- Improve immunity and potent and improve overall health.

Preparations: Like Restobal 500ml/1Lit Ayurvet Immunity enhancer and Geri forte 500ml/1Lit HDC may be used.

• Instant Energy Booster Sustain energy level and keeps animal active

Preparation: Like Gluca-Boost Liquid Natural Remedies Energy Booster may be used

Control and Prevention:

Control and prevention of lumpy skin disease relies on three tactics

1. Movement control (isolation and quarantine)
2. Vaccination
3. Management strategies.

Management strategies

• This involves a targeting all stages of the stable fly and mosquito life cycles to break the breeding cycle.
• Reduce the number of breeding and resting sites, fill pot holes
• Remove standing water from containers
• Ensure drains are free flowing
• Applying larvicide control in large bodies of water
• Applying adulticide control – Spraying and Fogging
• Maintaining mosquito and fly control records
• It also needs to consider tick control.
• Use of insect (ticks, flies, mosquitoes, fleas, midges) repellents to minimize mechanical transmission of LSD Movement control (isolation and quarantine)
• Lumpy skin disease moves into new territory principally by movement of infected cattle, and possibly by wind-borne vectors.
• Once in a new area, further spread probably occurs via insect vectors, and ticks have been implicated in maintaining the virus in between epidemics
• Control of cattle movement from uninfected to infected areas is an important measure to prevent the introduction of the virus.
• Slaughter of affected and in-contact animals, destruction of contaminated hides, and vaccination of at-risk animals is a common approach when the disease is introduced to a previously free area.
• Once the disease is in an area, control is by vaccination.
• Once in a herd, the disease is very difficult to eradicate due to subclinical infections and the presence of insects capable of spreading the virus.
• Immediate isolation of sick/infected animals from the healthy animals
• All biosecurity measures and strict sanitary measures for disposal of personal protective equipment (PPE) etc. used during sampling from affected animals should be followed Awareness campaign regarding the clinical signs and production losses due to LSD shall be conducted
• Disposal of carcass of LSD-affected animals o In cases of mortality, animal carcass should be disposed of by deep burial or burning.

Vaccination

• The only wɑy of preventínǥ LSD ís the vɑccínɑtíon of ɑll fɑrm ɑnímɑls Currently, líve ɑttenuɑted vɑccínes, bɑsed on LSDV strɑín, sheep pox vírus (SPPV), or ǥoɑt pox vírus (ǤTPV) mɑke up the mɑjoríty of commercíɑlly ɑvɑílɑble LSD vɑccínes.
• Most cattle develop lifelong immunity after recovery from a natural infection
• Calves born to immune cows acquire maternal antibody and are resistant to clinical disease until about 6 months of age.

Zoonotic Risk

It does not pose a risk to human health.