Are You Ready For West Nile?

The dog days of summer are here, and if weather patterns hold true, it will be hot and humid over a large area of the country. And if disease patterns hold true, humans and horse owners are starting the worst time of year for West Nile. Even though this disease will appear in many places this fall for the first time in U.S. history, the range of preparation varies from very prepared on the scientific level in some states, to totally unknowing on the part of horse owners in some regions that are at risk. Do you, as an educated, hands-on horse owner, know the signs of West Nile virus in the horse (or in a human)? Do you know how to make your property as mosquito-proof as possible? Can you identify regions that are at-risk for repeat outbreaks, or in the path of the spread of West Nile virus?

The "It won't happen here" attitude doesn't stop mosquitoes or birds from carrying this disease to new states and counties. Some of the top epidemiologists who deal with this sort of disease spread have told us the virus will continue to move west and south. It can take seemingly big jumps and miss areas, but usually there is a very discernable pattern that can be followed, if not predicted.

West Nile virus was first identified in the United States in late 1999. It appeared again in 2000. In those two years, West Nile claimed the lives of 28 humans and at least 32 horses (which were diagnosed). Others were sick and recovered. West Nile takes its toll especially on the very young, old, and infirmed (in humans and horses). But remember, horses are dead end hosts for this virus. That means even if a horse becomes infected, a mosquito can't bite the affected horse and spread the virus to another animal or human.

As of this writing in 2001, five states (Connecticut, Maryland, New Jersey, New York, and Rhode Island) have identified birds positive for West Nile virus. New Jersey also found a positive mosquito population. Fall is peak time for West Nile in mosquitoes, and they transfer the virus to people and horses.

This column isn't meant to scare you, but knowledgeable people are worried. That means horse owners and veterinarians in your area need to help educate other owners if you are in the path of this storm. In other words take heed of the Boy Scout motto and "Be Prepared!"

Universities and private practitioners are disseminating information and even holding short seminars on the topic of West Nile. There is plenty of information available on the web so that you can stay updated on where the virus has been found, what the symptoms are, and what you can do to help protect your horses (and yourself).

Since mosquitoes are found everywhere, it is the particular setting that determines your risk. If your horses are stabled most of the time with various insect controls in place (misting systems, screens, etc.), then the risks would be low even in an endemic area. If your horses are living mostly outdoors, ridden in the woods, or there are ponds or standing water in the vicinity of your horses' pastures or trails, then you would be at higher risk just because of the higher mosquito populations and exposure rate.

This isn't a panic situation. Researchers and veterinarians in the United States understand this disease much better as we start the third season of West Nile. We should also remember that other countries have been dealing with West Nile for decades.

However, it is up to each person to eliminate breeding sites for mosquitoes -- the first line of defense in this disease. Even if you get rid of everything on your property that could harbor mosquito larvae, if your neighbor doesn't do the same thing, then you are still at risk. This is truly a community effort, and the community now encompasses an entire region of the United States.

For more on West Nile, see our NewsFront section. You can stay updated on the progress of this disease through our web site at and with our free weekly electronic newsletter that you can sign up for at

About the Author

Kimberly S. Brown

Kimberly S. Brown was the Publisher/Editor of The Horse: Your Guide To Equine Health Care from June 2008 to March 2010, and she served in various positions at Blood-Horse Publications since 1980.

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