Equine influenza

[5] While equine influenza is historically not known to affect humans, impacts of past outbreaks have been devastating due to the economic reliance on horses for communication (postal service), military (cavalry), and general transportation.

Equine influenza is characterized by a very high rate of transmission among horses, and has a relatively short incubation time of one to three days.

[6] Clinical signs of equine influenza include fever (up to 106 °F [41 °C]), nasal discharge, have a dry, hacking cough, depression, loss of appetite and weakness.

[9] The virus is spread by infected, coughing horses in addition to contaminated buckets, brushes, tack and other stable equipment.

The influenza virus causes symptoms by replicating within respiratory epithelial cells, resulting in destruction of tracheal and bronchial epithelium and cilia.

[6] When a horse contracts the equine influenza virus, rest and supportive care is advised so that complications do not occur.

[citation needed] Vaccines (ATCvet codes: QI05AA01 (WHO) inactivated, QI05AD02 (WHO) live, plus various combinations) are a major defense against the disease.

[6] Standard schedules may not maintain absolutely foolproof levels of protection, and more frequent administration is advised in high-risk situations.

(Paillot, 2014[2]) An OIE expert surveillance panel annually assesses circulating strains and makes relevant vaccine recommendations.

[citation needed] The report notes the next recorded equine influenza case in 1299, the same year that a catarrhal epidemic affected Europe.

Spanish records noted cases in which "The horse carried his head drooping, would eat nothing, ran from the eyes, and there was hurried beating of the flanks.

Prevalence of influenza is found in historic records in the centuries of the Middle Ages, but direct implication of horses is not always clear.

On October 25, 1872, The New York Times reported on the extent of the outbreak, claiming that nearly all public stables in the city had been affected, and that the majority of the horses owned in the private sector had essentially been rendered useless to their owners.

The same report also took note of massive freight backups being caused by the lack of transportation ability that was arising as a result of the outbreak.

[22] Boston was hard hit by a major fire downtown on November 9 as firemen pulled the necessary firefighting equipment by hand.

[29] Australia had remained free of equine influenza until an outbreak in August 2007 when 10,651 horses were infected over a period of three months.

The cost to eradicate the disease was estimated at $1 billion and eventually the virus was successfully contained and Australia has returned to its equine influenza-free status.

In the latest incident, initially three vaccinated horses tested positive, resulting in the British Horseracing Authority (BHA) calling off races and putting in place "quarantine and biosecurity measures".