Transcript Edematous skin dis

Edematous skin disease (ESD)
Pseudotuberculosis in Egyptian buffaloes
Definition
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It is a mild contagious acute, subacute or chronic disease
of buffaloes which caused by corynbacterium
pseudotuberculosis (C. ovis). It is characterized by swelling
and suppurative in one or more of superficial lymph nodes
and/or its related lymphatic or general edema in the four
legs, intracutaneous nodules and ulceration of the skin
Etiology
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It is caused by C. Pseudotuberculosis alone or with other
pyogenic bacteria as Staphylococcus, Streptococcus and
Pseudomonas. It is believed that the disease might be
caused by C. pseudotuberculosis and filarial worms.
Morphology and staining:
C. pseudotuberculosis is facultative intracellular, Gram
positive, non-capsulated coccoid or filaments. It is
arranged in the form of palisade or Chinese letter.
Growth requirements and characteristics:
It grows well in media containing blood and serum.
Epidemiology
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Distribution: It is endemic disease and appears regularly
in Egypt. It was diagnosed for the first time in April 1960
at Senbellawene, Dakahalia province.
Animal susceptibility: Buffaloes are the main
susceptible animals.
Transmission:
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The main source of infection is discharged pus from infected
animals.
The disease is transmitted through the skin wounds and
abrasion. Also, insects are playing a major role in the
transmission of this disease.
Factors affecting on susceptibility
The disease is common in autumn and summer seasons.
All ages of buffaloes are susceptible and the age group
from 8 months to 3 years is more susceptible.
Both sexes are affected but females are more susceptible.
Animal crowding in muddy or dirty unhygienic stable are
more susceptible.
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Pathogenesis
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After infection of skin wound or abrasion, the organism multiplies and
secrets exotoxins and invade lymphatic vessels with formation of
subcutaneous swelling, nodules or abscesses along course of lymph vessels
(lymph vessels appear corded).
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These lesions appear mainly on chest, abdomen and legs or may be
developed all over body.
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Edematous swellings develop due to increase of permeability of blood
vessels and impaired drainage through early damaged lymphatics.
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Subcutaneous lesions along with draining lymph nodes are then undergo
suppuration and rupture discharging serosanginous fluid or creamy pus
stained with blood.
Occasionally, bacteremia develops with localization of the organism in
other internal organs.
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Clinical signs
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The incubation period is long, morbidity is high, mortality
is low and the course is long about 2-3 weeks and may
extend to 12 months
Acute form:
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It is characterized by mild fever, mild systemic disturbance,
decrease of appetite, decrease of milk production
painful local edema in one or both forelimbs, slight lameness
and enlargement and swelling of prescapular and/or the
precural lymph nodes.
The lymph nodes are firm, hot and painful. Puncture of these
swellings revealed serosanginous fluid or thick creamy green
pus tinged with blood.
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Subacute form:
 It is characterized by appearance of one or more
pimple-like nodules subcutaneously at any part of
the body.
 There is swelling and cording of the lymphatics with
formation of small abscesses along their course on
fore limbs, abdomen and thigh.
 These abscesses are spontaneously opened
discharging creamy pus tinged with blood.
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Chronic form;
 There are circumscribed nodules which gradually
develop into closed abscess containing thick
yellowish pus with formation of small area of skin
necrosis on the lateral or ventral aspect of the
trunk.
 Sloughing of the necrosed skin leaves crusts or
dried bloody exudates containing pus.
 Occasionally, bacteremia develops with localization
of the organisms in other internal organs resulting
debilitation and death
Postmortem lesions
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Carcasses show skin nodules, edematous swellings and
ulcerations.
Skin and subcutaneous tissues thickened, edematous and
adhered to each other and to the underlying muscles.
There is enlargement and suppuration of the superficial
lymph nodes.
There is congestion in liver, spleen and kidneys and
hemorrhagic foci in heart.
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Diagnosis
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Field diagnosis:
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It can be suspected on the basis of history,
epidemiology, clinical signs and PM
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Laboratory Diagnosis
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Samples: Samples includes pus from closed lesions of
untreated animals, swabs or biopsy, slices from skin and
parenchymatous lesions, lymph nodes, blood and serum.
Procedures:
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Direct microscopic examination of pus smears to
demonstrate short Gram positive Chinese letter bacilli.
Isolation and identification of the organism: inoculation of
the suspected material on the blood agar. The colonies
can be identified by biochemical reactions.
Serological examinations: They include CFT, FAT and toxin
neutralization test
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Differential diagnosis:
It can be confused with all skin affections as
skin abscess caused by Staphylococcus, skin
lesions of actinobacillosis, dermatophytosis,
dermatphilosis, lumpy skin disease,
pseudolumpy skin disease, pox. Ephemeral
fever, filariasis and hypoderma.
Treatment
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Systemic administration of large doses of antibiotics such as
pencillin (20,000-80,000 IU/kg for 5-7 days), tetracycline,
gentamycin and cephalosporin reduce the severity of the
infection. Also, supportive treatment is recommended such as
antipyretics, anti-inflammatory, antihistaminic, fluid therapy and
vitamins
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The closed lesions should be locally dressed with iodine or
icthyol ointment (5-10%) for ripening.
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The open lesions should be completely evacuated from pus
and irrigated daily with antiseptics as betadin until complete
healing.
Control
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Proper management and hygiene:
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The infected animal should be isolated and treated either
locally or systemically or both with the early treatment of the
skin abrasions.
All possible sources of the infection should be destroyed such
as removal of the contaminated surface soil of the animal yard,
Hygienic disposal of animal carcass, frequent cleaning and
disinfection of the stables, especially during the season of the
disease and insect control.
Vaccination:
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Vaccination trials were conducted by bacterin and toxoid
or vaccination of calves at 6 months of age by BCG which
enhance the non-specific immunity.