#17,553
Unusual diseases, or die-offs, in animals are always a concern - both for the animal's welfare and potential economic impact - and because of the possibility that an emerging disease may be - or become - a zoonotic threat as well.
In 2014, in Emerging zoonotic viral diseases L.-F. Wang (1, 2) * & G. Crameri wrote:
So media reports of as many as 10 sudden horse deaths, on three separate properties in Victoria, Australia since July 4th are worthy of our attention. Agriculture Victoria has posted the following statement on their website:The last 30 years have seen a rise in emerging infectious diseases in humans and of these over 70% are zoonotic (2, 3). Zoonotic infections are not new. They have always featured among the wide range of human diseases and most, e.g. anthrax, tuberculosis, plague, yellow fever and influenza, have come from domestic animals, poultry and livestock. However, with changes in the environment, human behaviour and habitat, increasingly these infections are emerging from wildlife species.
Sudden horse death investigations
Current situation
Agriculture Victoria staff are working with local veterinarians and experts to investigate the cause of multiple sudden horse deaths which have occurred since Tuesday 4 July.
The investigation is in its very early stages and extensive surveillance and testing is underway to understand the possible causes of the illness and death.
Horse owners should monitor their animals and report any sudden deaths or onset of illness in their horses immediately to their local vet, Agriculture Victoria or via the emergency animal disease hotline on 1800 675 888.
There have been ten confirmed sudden horse deaths on three separate properties. The properties are located on the Mornington Peninsula, south-east Melbourne and southwest Victoria.
It is not yet known what has caused these deaths. All horses died quickly with short term non-specific signs of illness and initial assessment had not revealed immediate common links.
There have also been several reports on social media channels of further affected properties. Agriculture Victoria is calling on these owners to make contact so they can assist with investigations.
Early testing for some infectious diseases has been negative. More testing is required, however, for a range of possible infectious and non-infectious causes.
Please do not share misinformation online or on social media.
One assumes that the `early testing' mentioned above would include Influenza A (equine H3N8), and presumably Hendra, a bat-borne virus (similar to Nipah) which first came to light in 1994 after the deaths of 13 horses and a trainer in Hendra, a suburb of Brisbane, Australia.
Since then, more than 40 outbreaks in horses, and a handful of human infections, have been reported in Australia. Two years ago researchers discovered A Novel Variant Of the Hendra Virus which had previously eluded tests.
Australia has reported only one outbreak of Equine influenza (in 2007), but they maintain a long list of other notifiable equine diseases, including arboviruses spread by biting insects.
Outbreaks can have huge economic impacts. From the 2022 edition of the Victorian Government State Emergency Animal Disease Response Plan, a brief summary of the 2007 Equine Influenza outbreak:
In 2007, EI was detected in a horse in New South Wales (NSW) after the virus escaped quarantine. After six months, and a total estimated cost of $571 million to Australian governments, the disease was eradicated through the use of vaccination and strict movement controls. Australia is the only country in the world to have eradicated EI following an incursion.
For now, there are no obvious suspects, and there is no indication that there is a threat to human health. It is even possible that there is an environmental, or non-infectious disease, cause for these deaths.
Stay tuned.Given the efforts Australia puts into keeping agricultural diseases out of their country, I expect this investigation will move swiftly.
