The return of wild migrating birds for the winter season has again put the poultry industry across Ireland on high alert to the dangers posed by Avian Influenza (AI), or as it is commonly known, bird flu.
The H5N8 strain of the virus is highly pathogenic, and if confirmed at a site, means culling of birds, and establishment of a protection zone of 3km and a surveillance zone of 10km around the infected premises. Trade in live poultry or poultry products to other countries is restricted from these zones, so the impact on the economy is potentially significant.
There are two key areas – people and wild birds
With no treatments or vaccines available locally, the only preventative measure available to flock owners is to keep it out by practising good biosecurity.
“There are no other preventative strategies for AI available in this country. There are two key areas – people and wild birds,” explained Daniel Parker, a veterinary adviser to the British Poultry Council, speaking at an online event.
He advised flock owners to keep visitors to an absolute minimum, and to maintain a visitors’ book that includes contact details, previous sites visited and what sites they are going to next. “This is really important information should your site become an infected premises,” he said.
Visitors should also wear protective clothing, and be given access to foot dip and hand-washing facilities.
Wild bird access
For birds in free-range systems, he highlighted the risk of having pooled water on the range, as this will inevitably attract wild waterfowl (such as ducks, geese and swans) on to the site, significantly increasing the risk of AI being spread.
However, for the poultry industry as a whole, perhaps the main weakness is the potential that AI could make its way into small backyard flocks. Parker emphasised that his message around good biosecurity applies equally to these small flock owners.
Birds should not be fed out on the range, and if you do feed outside, use covered feeders
“Ideally don’t mix bird species, especially water fowl with other poultry species. If you have water fowl there is a chance that they will call in wild water fowl, and we want to avoid that,” he said.
Birds should not be fed out on the range, and if you do feed outside, use covered feeders. Feed spillages should also be cleared up, and birds should not have access to open water, advised Parker.
All wild birds, dogs, cats, other livestock and vermin can spread disease and should be kept out of poultry houses and feed stores.
When it comes to clinical signs of the disease, he said that this can be quite variable and dependent on the strain of AI and the species of poultry involved. Water fowl tend to be more resilient, and might not show any clinical signs of disease, whereas turkeys tend to be the most susceptible.
The egg shell colour may be affected. Egg production will almost certainly drop
“The key things are lost appetite and increased mortality. There may be coughing and sneezing, there may be diarrhoea, or swollen heads and wattles. The egg shell colour may be affected. Egg production will almost certainly drop,” said Parker.
Where there is unexplained mortality or egg production drop he said it is vital to consult a specialist poultry vet. “It is far better to report and get advice, than harbour disease and potentially spread it to other poultry keepers” he concluded.
H5 and H7 strains of AI are classed as notifiable diseases, so poultry keepers must report relevant cases to respective Department of Agriculture vets, and government must take action to control outbreaks.
The H6 strain is not deemed to be a notifiable disease. Earlier in 2020 the low pathogenic H6N1 strain was confirmed in a number of flocks in border counties. It causes mild symptoms and production loss.
But because it is not notifiable, there is no automatic compensation scheme available from government if industry decides to cull infected birds.