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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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