Avian Influenza In Small Flock Chickens

When you live on an island you can sometimes be lulled into a false sense of complacency that geography will protect you. Distance, to some degree, is a buffer, but when people and animals move between communities they may inadvertently bring trouble with them. This week, in my neck of the woods, the problem is avian influenza.

As of this moment there are currently nine outbreaks of A.I. (bird flu) in the province of British Columbia, which is the size of France and Germany combined, or one and a half times the size of Texas. Huge, right? And I live on Gabriola, a tiny island (14 km long x 2.5 km wide), nestled between mainland B.C. and Vancouver Island, and one of those affected places. What are the odds of that?

What is Avian Influenza?

AI is a naturally occurring virus that many birds are susceptible to becoming infected by, whether they become symptomatic or not. It can survive outside a host for long periods depending on salinity, pH, organics, temperature and humidity of the environment: up to one month inside a poultry house at 4.5ºC/40ºF and in freshwater lakes for over 30 days at freezing temperatures.

The A.I. virus is divided into high (HPAI) and low pathogenic (LPAI) strains based on their ability to cause disease. Waterfowl are a natural reservoir for low pathogenic strains that cause minimal or no signs of disease in poultry and wild birds and, is therefore, not a serious threat. High pathogenic, however, causes severe disease in domestic poultry who have no natural immunity, with a high mortality rate. There is no cure and vaccines are not widely available.

Just in case you’re panicking about contracting H5N1 from your flock – it’s possible, but this isn’t a common occurrence. You’re much more to get sick from one of the common strains of flu that circulate each year. And it’s totally safe to eat poultry or eggs. Thankfully the virus isn’t spread from hens to chicks via the egg.

A.I. is further divided into subtypes based on the two proteins, haemaglutinin (H) and neuraminidase (N), found on their surfaces. There are 16 H types and 9 N types, which can be found in different combinations. H5N1 is a high pathogenic form that causes disease in chickens and other species of birds, which affects multiple internal organs. Mortality rates can reach 80-100% within 48 hours.

In the last two decades high pathogenic A.I. has spread throughout parts of Asia, Africa, the Middle East, Europe and North America. The H5N1 strain is considered endemic and large outbreaks occur intermittently.

In 2004, British Columbia experienced an outbreak that affected the highest concentration of commercial chicken farms in the province. Before the virus was controlled, 17 million chickens in the Fraser Valley were sent to slaughter to prevent the further spread of the devastating disease. In addition, 553 small flocks that were situated within a designated radius of an A.I. positive commercial farm were also euthanized as a preemptive measure.

Unfortunately the strain that my community is currently contending with is also H5N1. A neighbouring flock was wiped out and due to Gabriola Island’s size (58 square kilometres), all small flocks are situated in the control zone. So far, we haven’t heard from authorities what that means for those of us with healthy flocks, except the usual advice about adhering to strict biosecurity practices. Further measures include the prohibition of moving birds off, or onto, your property, and selling eggs or poultry.

Transmission

• Fecal-oral contact, meaning that birds ingest infected poop from contaminated surfaces or infected food and water supplies
• Contained in secretions from the nose, mouth and eyes
• Wild birds may transfer the virus from their feet, feathers or dander
• The A.I. virus can spread from wild birds to poultry, between poultry flocks and from chickens to wild birds

Prevention

• Restrict contact with wild birds and other animals (e.g. don’t throw scratch or leave feed on the ground; pen your flock; install overhead netting or tarps)
• Prevent your flock from accessing wetlands where waterfowl frequent
• Remove wild bird feeders
• Frequently disinfect coops, waterers and feeders
• Install disinfectant foot dips at the entrance to your pen or coop
• Use dedicated coop clothing and footwear that are only worn on your property
• Recognize the signs of A.I. and report early
• Restrict exposure to visitors (i.e. no outsiders can enter your pens or coop, limit vehicle access)
• Quarantine new birds
• Bury or burn corpses that are not being sent in for necropsy to deter scavenger birds (e.g. ravens, hawks, eagles) from contracting the virus

Symptoms

• Lack of energy, movement or appetite
• Decreased egg production
• Swelling around the head, neck and eyes
• Coughing, gasping for air or sneezing
• Nervous signs, tremors or lack of coordination
• Diarrhea
• Sudden death

It’s critical that you send birds that have died with any of the above signs for confirmation of cause of death. Agriculture departments in both Canada and the USA are tracking confirmed cases in both wild and domestic birds and you can check local maps to see if you are close to an affected zone. I think many bird deaths have gone unreported so there are probably more cases and outbreaks than we’re aware of.

Next Steps

I’ve scoured the government website to figure out how that might impact me. According to their site: “If a notifiable case of AI is confirmed, all birds on your property will be humanely destroyed. Poultry products, such as eggs, will be destroyed as they are considered to pose a risk of spreading the AI virus to other birds. Flocks on other farms in the surrounding area will also be quarantined and tested. If the particular virus present on your farm is determined to be highly pathogenic, under special conditions, all the poultry on commercial operations within one kilometre of your farm may also be pre-emptively destroyed.” (Just to translate, pre-emptive means they don’t have to have tested positive to be on the kill list).

There is nothing worse than hearing rumours and speculating what that might mean for your future. I’ve figured out where the confirmed case is and they are much too close for comfort – perhaps less than two kilometres away, as the crow flies.

At this stage, I’ve done all I can to protect my birds and am crossing my fingers that’s enough to save them. I’m hoping this is also a wake up call for other small flock keepers to practice more stringent measures to routinely keep our birds safe and prevent the spread of disease.

The CFIA protocol is to deal with the outbreak and then monitor the surrounding 3km infected zone and 10km primary control zone for a minimum of 14 and 28 days, respectively, to confirm there are no further cases.

For further information contact your local Ministry or Department of Agriculture.

In British Columbia, report suspected cases of A.I. in wild birds to the Wild Bird Mortality Hotline 1-866-431-2473. To send a chicken for a necropsy contact the Animal Health Centre 1-800-661-9903

Useful sites: British Columbia Animal Health Centre; Canadian Food Inspection Agency (CFIA); United States Department of Agriculture (USDA) and Wildlife Health Information Sharing Partnership (WHISPers).

Credits: Dr Victoria Bowes, DVM/Avian Pathologist; Animal Health Centre; British Columbia Ministry of Agriculture; Canadian Food Inspection Agency (CFIA); Ducks Unlimited; Extention Foundation Campus. Featured photo: Promega Connections