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Animals and Anthrax

Dr.Kedar Karki

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Introduction

• Anthrax is an acute infectious disease of almost all warm-blooded animals including humans. In animals, the disease is characterised, in most instances, by sudden death.

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Introduction

• Anthrax is caused by the bacterium Bacillus anthracis that belongs to a group of bacteria that have the capability of forming spores.

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Epidemiology?

•The disease occurs world-wide.

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Animal species can be affected by anthrax?

•Cattle, sheep, goats, horses, donkeys, pigs, dogs, etc...

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Clinical Signs in Animals

• Signs differ by species–Ruminants at greatest risk

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Three forms of illness

–Peracute

•Ruminants (cattle, sheep, goats, antelope)

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Three forms of illness

–Acute

•Ruminants and equine

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Three forms of illness

–Subacute-chronic

•Swine, dogs, cats

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Ruminants

• Peracute infection

–Rapid onset

–Sudden death

–Bloody discharge from body orifices

–Incomplete rigor mortis

–Rapidly bloat

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Ruminants

• Acute infection: 1-3 days

–Fever, anorexia

–Decreased rumination

–Muscle tremors

–Dyspnea

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Ruminants

–Abortions

–Disorientation

–Bleeding from orifices

–Hemorrhages on internal organs

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Ruminants

• Chronic infection

–Pharyngeal and lingual edema

–Ventral edema

–Death from asphyxiation• Treatment successful if started early

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Differential Diagnosis

• Blackleg

• Botulism

• Poisoning– Plants, heavy metal, snake bite

• Lightening strike

• Peracute babesiosis

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Equine

• Ingestion– Enteritis, severe colic,

high fever, weakness, death within 48-96 hours

• Insect bite/vector– Hot, painful swelling– Spreads to throat,

sternum, abdomen, external genitalia

– Death

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Swine

• Sudden death without symptoms

• Localized swelling of throat

• Death by asphyxiation

• Ingestion of spores– Anorexia, vomiting, enteritis

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Dogs & Cats

• Relatively resistant– Ingestion of contaminated raw meat

• Clinical signs– Fever, anorexia, weakness– Necrosis and edema of upper GI tract– Lymphadenopathy and edema of head and

neck– Death

• Due to asphyxiation, toxemia, septicemia

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Diagnosis and Treatment

• Necropsy not advised!

• Do not open carcass!

• Samples of peripheral blood needed– Cover collection site with disinfectant soaked

bandage to prevent leakage

• Treatment – Penicillin, tetracyclines

• Reportable disease

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Prevention and Control

• Report to authorities

• Quarantine the area

• Do not open carcass

• Minimize contact

• Wear protective clothing– Latex gloves, face mask

• Vaccination of susceptible animals

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Prevention and Control

• Burn or bury carcasses,bedding, other materials

• Decontaminate soil

• Remove organic material and disinfect structures

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Disinfection

• Effective disinfection can be difficult• Prevention of sporulation best• High pressure cleaners discouraged• Soil

– 5% lye or quicklime– Hydrogen peroxide, peracetic acid or

gluteraldehyde

• Bleach 1:10 dilution– May be corrosive

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Disinfection

• Preliminary disinfection– 10% formaldehyde– 4% glutaraldehyde (pH 8.0-8.5)

• Cleaning– Hot water, scrubbing, protective clothing

• Final disinfection: one of the following– 10% formaldehyde – 4% glutaraldehyde (pH 8.0-8.5)– 3% hydrogen peroxide,– 1% peracetic acid

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