are administered if the fever reaches greater than . If complications occur, such as the onset of pneumonia, or if the fever last more than 3 to 4 days, antibiotics are often administered. Prevention Prevention of equine influenza outbreaks is maintained through vaccines and hygiene procedures. Isolation of horses for two weeks is common practice when they are being moved to a new environment. Vaccines Vaccines (ATCvet codes: inactivated, live, plus various combinations) are a major defense against the disease. Vaccination schedules generally require a primary course of vaccines, followed by booster shots. It is recommended that horses be vaccinated against equine influenza annually, and competition horses that travel frequently be given a booster every six months as they are at higher risk of contracting the virus. Foals are initially vaccinated at six months of age with a booster 3 to 6 weeks later and again between 10 and 12 months. Standard schedules may not maintain absolutely foolproof levels of protection, and more frequent administration is advised in high-risk situations. Equine influenza virus (EIV) undergoes continuous antigenic drift, and vaccine protection from immunogenic stimulation is maximised when vaccines strains have greater homogeneity to circulating strains. Subclinically affected vaccinated horses can shed live virus and represent a threat to unvaccinated or inappropriately vaccinated horses. Neutralising immunity leading to an absence of infection is rare. (Paillot, 2014) An OIE expert surveillance panel annually assesses circulating strains and makes relevant vaccine recommendations. The UK requires horses participating in show events be vaccinated against equine flu, and a vaccination card must be produced; the International Federation for Equestrian Sports requires vaccination every six months. History A comprehensive report describing the disease—compiled in response to the 1872 outbreak of the disease in North America—provided a thorough examination of the history of the disease. Early records The report notes putative cases dating as far back as Hippocrates and Livius. Absyrtus, a Greek veterinarian from 330 CE, described a disease in the horse population having the general characters of influenza, which the report mentions as the earliest clear record of equine influenza in the lower animals. 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. The malady was epidemic,