Wed, 07 June 2017

ALERT! Avian Influenza (AI)

1. What is Avian Influenza (AI)?
  • AI is caused by influenza virus (not to be confused with seasonal human influenza)
  • AI can affect food producing birds (chickens, turkeys, quails etc.), pet & wild birds
  • AI viruses can generally can be classified into two categories:
  1. low pathogenic (LPAI) that typically causes little or no clinical signs in birds &
  2. highly pathogenic (HPAI) that can cause severe clinical signs and/or high mortality in birds.
  • Some strains of AI can be transmitted to humans but fortunately H5N8 has not been shown to infect humans yet
2. How is the disease transmitted and spread?
  • Wild birds normally can carry AI viruses in their respiratory or intestinal tracts and usually do not get sick.
  • AI viruses can be spread through direct contact with secretions from infected birds, especially faeces or through contaminated feed, water, equipment and clothing.
  • Apart from being highly contagious among poultry, avian influenza viruses are readily transmitted from farm to farm by the movement of domestic live birds, people (especially when shoes and other clothing are contaminated), and contaminated vehicles, equipment, feed, and cages.
  • Highly pathogenic viruses can survive for long periods in the environment, especially when temperatures are low
  • AI is a notifiable disease i.e. it has to be communicated to the Department of Veterinary Services (DVS) immediately to stop the spread
3. What are the clinical signs of the disease?
  • In the mild form signs of illness may be expressed only as ​ruffled feathers, reduced egg production, or mild effects on the respiratory system.
  • In the severe form of the disease, the virus not only affects the respiratory tract but also invades multiple organs and tissues that can result in massive internal haemorrhaging.
  • Some or all of the following clinical signs are evident in birds infected with a highly pathogenic strain of AI (including H5N8 strain):
  1. quietness and extreme depression
  2. sudden drop in production of eggs, many of which are soft-shelled or shell-less;
  3. wattles and combs become swollen and congested;
  4. swelling of the skin under the eyes;
  5. coughing, sneezing and nervous signs;
  6. diarrhoea;
  7. haemorrhages on the hock;
  8. a few deaths may occur over several days, followed by rapid spread and a mortality rate that can then
  9. approach 100% within 48 hours.
4. Measures that are recommended at the farm level include:
  • Have a footbath on all entrances with Paragon Plus at 1:200 (scientifically proven to kill AI virus at that rate) Practice strict biosecurity
  • Ensure that wild birds, doves, sparrows etc cannot enter the chicken houses to feed
  • Make sure no visitors are allowed on your farm and avoid visiting other poultry farms Do not share equipment and other poultry farm instruments with other farms
  • Make sure you maintain sanitation of property, poultry houses and equipment
  • Avoid the introduction of birds of unknown disease status into your flock;
  • Closely monitor your flocks for any signs of AI and quarantine farm if suspicious
  • Report any drastic increase in mortality in your flock to the Department of Veterinary Services Keep poultry away from areas frequented by wild fowl
If the disease is detected, generally a 'stamping out' (culling) policy is used in the efforts to eradicate the disease

For any further assistance please call our technical team on 04 753846-8 or email on