When West Nile Virus reached America about 13 years ago, it hit the ground running. Within a few short years it made its presence known in almost every state, from coast-to-coast.
Though many animals that contact the virus, including humans, usually show no symptoms, such is not the case with birds and horses.
According to the American Association of Equine Practitioners, about one-third of horses who exhibit clinical signs of WNV infection, which is transmitted by mosquitoes, will die or be euthanized.
In 1999, there were 25 reported equine cases of the West Nile Virus in the U.S. By 2002, that figure ballooned to more than 15,000.
Ok, now for the good news: in 2011, the number of horses diagnosed, nationwide, fell to 87.
The amazing decline is all due to the equine West Nile vaccine and conscientious horse owners. The vaccine, developed a decade ago, is now administered as routinely as those for equine flu and tetanus.
And like other vaccines, the one for WNV only helps before the fact -- to prevent infection, not cure it. Because it can take up to six weeks for a horse to develop full immunity after receiving the vaccination, most horses, such as those at Altadena Stables, are on a six-month schedule.
In the equine world, the vaccine has proved a life saver. However, the vaccine only works if it's used. Cases of equine WNV are up in 2012, to over 100 year-to-date. When was your horse last vaccinated? Maybe it's time to call the vet.