Horses are a common sight on many farms in the Ozarks.
Used for work like gathering and sorting cattle, or for sheer enjoyment like a trail ride with friends, horses play a big part on a farm or ranch. Horse health often differs from that of other livestock, so most horse owners try to stay up to date on what to vaccinate for.
A horse is an investment and a friend, and you want to protect your investment – but do you still need to protect them from West Nile Virus?
What Is West Nile Virus?
West Nile Virus is a mosquito-borne virus that is found in wild birds. The disease that stems from this virus was first discovered in Africa in 1937 – it was not found in North America until 1999.
West Nile virus is maintained in nature through a complex life cycle involving wild birds and mosquitoes. When a mosquito feeds on an infected bird, it can pick up the virus and transmit it to other, uninfected birds. Occasionally, infected mosquitoes will feed on mammals such as horses, dogs, cats and humans, and transmit the virus to them. Mammals are dead-end hosts, however, and do not contribute to the transmission cycle, according to the Missouri Department of Health and Senior Services.
Diagnosing, Treating and Preventing West Nile Virus
If a horse receives a bite from a mosquito carrying West Nile, the incubation period for the disease is five to 15 days. The most common symptoms displayed by horses suffering from West Nile Virus are stumbling, uncoordination, weak limbs, partial paralysis, muscle twitching and in some cases, death. Other symptoms include depressed behavior, impaired vision or collapse. If you notice your horse displaying any of these symptoms, contact your veterinarian immediately.
Treatment for West Nile Virus may differ depending on your region.
“While most horses that recover from West Nile Virus have a full recovery, about 40 percent have some long term effects,” said Marci Crosby, MU Extension Equine Program coordinator at the University of Missouri. She also noted that this disease is fatal in one-third of all cases.
As always, prevention is better than the cure. Horses should be vaccinated annually for West Nile Virus, according to the American Association of Equine Practitioners.
“The vaccine is effective and safe, and helps to safe guard horses from the severe form of the disease,” said Crosby.
There are also management practices to decrease the risk of your horse receiving a bite from an infected mosquito.
“West Nile is only spread through mosquito bites, so anything that decreases mosquito habitat (standing water) and decreases a horse’s exposure to mosquitos (sprays, fans, etc.) can be beneficial. Most fly repellents work for only short amounts of time, so owners can get the most benefit by removing all standing water around their barns, or using mosquito dunks in standing water,” she said.
West Nile Virus Risk in the Ozarks
To date, there have been 337 reported cases of West Nile Virus in horses in the United States. So where does Missouri fall? “Missouri doesn’t have a high level of infection, but the disease is present,” noted Crosby.
There have been 13 reported cases of West Nile Virus in Missouri.
