African Horse Sickness

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African Horse Sickness
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• African Horse sickness (AHS) is a viral disease
  with an extremely high mortality rate.  The key
  to treating AHS is to learn about it, recognise
  early symptoms and, primarily, prevent the
  disease as best as possible.  AHS is highly
  infectious but not contagious.
• AHS may affect horses, donkeys or mules.  The
  virus is spread by midges (Culicoides midges) so
  preventing the disease largely depends on
  controlling these midges.  The virus has 9
  serotypes which can be found in various places in
  South Africa.  AHS is prevalent in the warm,
  rainy seasons when the midges are in abundance. 
  Most horses get bitten by midges at sunrise or
  sunset, when midges are most active. 

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What are the Symptoms?

• AHS manifests in 3 different forms, lung form
  (dunkop), heart form (dikkop) and mixed form. 
  The mixed form is a combination of the lung and
  heart form.
• Lung form (dunkop) symptoms are
• Extremely high fever
• Difficulty breathing with the mouth open and the
  head may hang down.
• Discharge from the nose which is foamy or frothy.
• Sudden death very high mortality rate (up to
  90).
• Heart form (dikkop) symptoms are
• Peri-orbital swelling (swelling around the eyes).
• Swelling around the head.
• Fever
• Difficulty swallowing.
• Lower mortality rate (- 50)
• Death may result in 4-8 days after the fever
  shows.

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Diagnosis

• Your veterinarian will be able to confirm the
  disease by taking a blood sample during the fever
  episodes of the disease.  The virus will be
  isolated in a laboratory from this blood sample.
  AHS is a controlled disease which means if you
  suspect your horse has AHS you must notify your
  veterinarian immediately, who will then notify
  the state veterinarian.

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How can I prevent the disease?

• Vaccination
• Vaccinations usually happen twice a year by your
  veterinarian.  They should be done before any
  outbreaks of AHS.  It is important you consult
  with your veterinarian before vaccinating.
• Repellents
• Stables should be safely fumigated to get rid of
  any midges.  Please ensure food and water is not
  contaminated during this process. 
• Shade cloth also helps to keep midges out of the
  stables.

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• Prevent midges from breeding
• The perfect breeding area for midges is moist
  environments, especially rich, organic soil.  Wet
  and humid environments are best for them. Horse
  dung must be removed regularly as this will
  attract midges and is a great place for them to
  breed. 
• Stable Horses
• This should be done when the midges are most
  active late afternoon, overnight, until about
  mid morning.
• Fans
• Fans provide ventilation in stables which
  reduces the horse odour, which midges may be
  attracted too.
• Treatment
• Treatment is purely supportive.  Given the high
  mortality rate, preventive care is crucial in
  trying to control this disease.