Is equine flu contagious? (+ six more common questions about equine flu)

The equine influenza (flu) virus is specific to horses and causes a multitude of symptoms including a raised temperature, lethargy and coughing. Here, vet Ricky Farr MRCVS answers seven common questions about equine flu.

Can a vaccinated horse still contract flu?


Yes, but clinical signs in a vaccinated animal would be minimal and the recovery time quicker.

Think of it like human flu: vaccinated people don’t get full-blown flu, but they may get a snotty nose and still be able to get out of bed and work.

Does equine flu kill?

Flu is unlikely to kill your horse, but if untreated it can be a primary trigger for pneumonia in foals, which may result in death.

Is equine flu contagious?

Yes, very – and it spreads fast. Flu’s incubation time is between one and three days.

How does equine flu spread?

Equine flu spreads in two ways:

Direct transfer – through horse-to-horse contact, mainly through coughing.

Indirect transfer – from the horse to its rider or tack for example.

How far can equine flu travel?

A long way – up to 5km.

Does my old horse still need vaccinating for equine flu?

Yes – the increasing geriatric population are just as susceptible due to concurrent consequences of age-related problems.

What is herd immunity?

Herd immunity occurs when a significant portion of a group is vaccinated, providing a measure of protection for individuals who have not yet developed immunity.

In these situations, the disease is unable to spread because there are too few susceptible horses left to propagate the outbreak.

In Britain, it’s estimated that less than 50% of horses are vaccinated against flu, and this needs to increase to 70% in order to achieve herd immunity.

Until vaccination levels improve, we will continue to see outbreaks of flu in the UK.

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