The first reported equine case of West Nile Virus has been diagnosed in Colorado as of August 14, 2013. The West Nile Virus was confirmed in a 3 month old colt from Montezuma County.
West Nile Virus - Zoonotic disease affecting horses and humans
The first reported equine case of West Nile Virus has been diagnosed in Colorado as of August 14, 2013, in a 3 month old colt.
According to Colorado State Veterinarian, Dr. Keith Roehr, “West Nile Virus is a disease that threatens the health of humans, horses, and other animals. This is the time of year when we are most likely to see it reported in horses. It is difficult to project how many cases we may see in the coming months.”
The transmission of the disease varies from year to year and depends on a number of factors including mosquito numbers. The WNV can be carried by infected birds and then spread locally by mosquitoes that bite those birds. The mosquitoes can then pass the virus to humans and animals.
West Nile virus is transmitted from avian reservoir hosts by mosquitoes, and infrequently by other bloodsucking insects, to horses, humans and a number of other mammals.
Horses and humans are considered to be dead-end hosts for West Nile Virus. The virus is not directly contagious from horse to horse or horse to human, and indirect transmission via mosquitoes from infected horses is highly unlikely as these horses do not circulate a significant amount of virus in their blood.
Prevention of West Nile virus in horses
Vaccination against the West Nile virus is the best method of prevention. A USDA licensed vaccine is recommended as a core vaccine and is an essential standard of care for all horses in North America.
In addition to a sound vaccination protocol recommended by a veterinarian, simple insect control measures should be utilized and insect repellents used when horses are in areas exposed to mosquitoes. Horses should be stabled during dusk and dawn hours and other times when mosquitoes are present and good use of fan to insure insects don't invade barn and stable areas is important.
Horse owners should eliminate opportunities for mosquito breeding by draining wet areas of pasture, filling puddles, repairing eve troughs, gutters, and clearing any containers that might hold even small pools of water.
Draining water tanks once or twice weekly should be a priority during mosquito season. Additionally, controlling mosquitoes in ponds and large water containers through the use of larvacides and fish helps keep the mosquito population down.