The UK and Europe is currently experiencing its largest outbreak of bird flu – its official name: highly pathogenic avian influenza, or H5N1 virus. The outbreak, which started over a year ago, has accelerated recently. There have been almost 100 confirmed cases in the UK in the last month and farmers now have been instructed to apply harsher measures to stop the spread of the virus. But what about other pets? Are they at risk too?
Firstly, what is bird flu?
Avian influenza is a very contagious viral disease affecting the respiratory, digestive, and nervous system of birds. It is devastating to birds, causing wide-spread mortality around the world, particularly in Europe and North America. Unfortunately, the R number (the word we have all become familiar with in the last couple of years) for this virus is high: 1 bird might (at least in theory) infect as many as 100 others according to some studies. Most studies do suggest a lower value, but certainly, H5N1 is one of the most infectious avian influenza strains known.
Typically, symptoms in birds develop suddenly, including sudden death, swollen heads, dullness, closed runny eyes, difficulty breathing, blue discolouration of the comb and wattles, diarrhoea, and decreased egg production. Some species of birds, such as ducks, geese and swans can be infected by bird flu and act as carriers for the virus without showing any signs of illness.
Although rare, human infections have been known to occur when they are in close contact with infected birds and are exposed to enough of the virus through their eyes, nose, or mouth. It can cause serious illness. Fortunately, no sustained human-to-human transmission has so far been noted in this outbreak.
Bird flu outbreaks have happened often in the past and tend to ‘fizzle out’ with appropriate biosecurity measures taken by poultry farmers. However, this outbreak is sticking around, and the concern virologists have is that genetic mutations of the virus have increased its ability to replicate (allowing it spread easily) and allowed the virus to infect a wider range of bird species than perhaps previous strains were able to.
This current strain also has a better ability of jumping to mammals. However so far, it is unable to spread from one mammal to another.
Should I be worried about my dog?
Historically, dogs are not natural hosts of bird flu, but they have been rarely known to contract it. There was a case reported and confirmed in Thailand in 2006, after the dog ingested an infected duck during an outbreak. So while the risk is very low, it is a situation that requires vigilant monitoring.
Seroconverting means that antibodies (the immune system’s fighting protein) have been found in the blood, either in response to infection or vaccination. A 2007 study showed that dogs exposed to H5N1 seroconverted, meaning that they were infected with the virus. Experimental outcomes demonstrated that some excreted the virus without showing any symptoms of disease.
In 2004, influenza A made a jump from horses to dogs, beginning in Florida. This caused a widespread infection in over twenty US states and resulted in serious illness and death in affected dogs. It is when we know that influenza A (H3N8) became established in dogs. We know, historically, that influenza can jump between species, and become established in a new host, namely dogs. Whilst there is no cause for worry at the moment, we still must pay special attention to any changes in the outlook for avian influenza infection, meaning that we must take some precautionary measures with our pets.
What safety measures should I take?
In areas where there have been reported outbreaks of bird flu, dogs’ contact with birds and poultry should be prevented. Stop your dog from picking up and eating any sick or dead wild birds, even if outbreaks haven’t been reported in your area. If they are likely to put their nose to the ground and flush out any carcasses, keep them on the lead. This is also to help prevent the spread of H5N1 to other birds.
As bird flu is a notifiable disease, it is important that suspect cases are reported. The current guidelines to call Defra include finding:
- 1 or more dead birds of prey
- 3 or more dead gulls or waterfowl (swans, geese, and ducks)
- 5 or more dead birds of any species
If you do see a dead or visibly sick wild bird, don’t touch, or pick up the bird. Instead, report it to the RSPCA (SSPCA in Scotland) or your local council.
If you keep any captive birds such as poultry and you suspect bird flu, you must report it to DEFRA.
Keep your dog’s food covered and stored, and ensure you only give them fresh water. Feeding raw poultry is not recommended. Although infected poultry meat is unlikely to make it down the food chain when bought, cooking food thoroughly decreases the risk of infection.
So how big is the risk of bird flu to dogs?
Overall, the risk of a dog contracting bird flu is low: but not zero, so extra precautions are needed while the avian influenza epidemic is ongoing.