Equine influenza: What is it and does it affect humans?
Thursday 7 February 2019 11:54, UK
Horse racing in Britain has been cancelled due to an equine flu outbreak after three horses were diagnosed.
Just three cases may not seem like many to cause a multi-billion pound industry to shut down, but they were all vaccinated, which the British Horseracing Authority (BHA) said was "a cause for significant concern".
Equine influenza is highly infectious to horses, mules and donkeys and is caused by strains of the Influenza A virus.
In the UK all horses participating in events, from horse racing to dressage, must be vaccinated every six months and must produce a vaccination card at events.
What are the risks of equine influenza?
It is the most potentially damaging respiratory virus for horses in the UK, the BHA said.
For unvaccinated horses with no prior exposure to the virus there is nearly a 100% infection rate.
What are the symptoms?
Symptoms include a high fever, a dry, hacking cough, nasal discharge, depression, loss of appetite and weakness.
It can cause horses to get pneumonia.
How is it spread?
Equine influenza can be spread through the air by horses coughing.
Contaminated stable equipment, from buckets and brushes to tack and clothing, can also spread the virus.
Once enough of the virus is in an area it spreads quickly, especially in crowded areas such as race courses or during transportation.
The movement of horses for international competitions and breeding has increased the likelihood of equine influenza being transmitted around the world.
What is the treatment?
Vets recommend that horses with equine influenza need to rest for at least one week for every day the fever persists, with a minimum of three days' rest.
Anti-inflammatory drugs are given to horses whose fever reaches higher than 40C (104F).
If the fever lasts more than three to four days, or if pneumonia starts to set in, then they are given antibiotics.
Infected horses should be placed in isolation and no new animals should come to where they are, according to the World Organisation for Animal Health.
Yards and anywhere the infected horses have been should be cleaned and disinfected, with common disinfectants easily killing the virus.
How long does it take for a horse to recover?
Horses that are mildly affected will recover within two to three weeks.
For those severely affected it can take up to six months to recover.
How can it be prevented?
Trainers have been told to ensure their horses have a booster vaccination if they have not had a vaccination in the past six months.
They should also be "extra-vigilant about biosecurity".
Vaccination usually keeps equine influenza at bay, but there are so many strains vaccination does not always prevent infection.
Can it affect humans?
Equine flu cannot be passed on to humans, however the financial ramifications can be high, especially in the horse-racing industry which is worth £3.54bn to the UK.
Humans can be transmitters of the virus.
Have their been outbreaks before?
Equine influenza is prevalent in most of the world, except Australia, New Zealand and Iceland, where they have managed to keep the virus out, or eradicate it.
In 1872 the first modern outbreak was recorded, with The Great Epizootic of 1872, across North America when horses were used for transport and farming.
Known as the "most destructive recorded episode of equine influenza in history", about 10% of horses died after the majority were infected.
In 1987 more than 27,000 animals died in India during an equine flu epidemic.
In 2004 there was an outbreak in dogs caused by a strain of equine influenza.
Australia remained free of equine influenza until 2007 when 10,651 horses were infected over three months.
It cost the country an estimated £774 million to eradicate and return Australia to its equine influenza-free status.