How Does West Nile Affect Horses?

In horses, West Nile Virus causes an encephalomyelitis, or brain and spinal cord infection. Most horses bitten by a mosquito infected with West Nile Virus will not develop clinical disease. They develop an asymptomatic infection, eliminate the virus and are none the worse for it.

What are the signs of West Nile in horses?

Symptoms of severe illness include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis.

What are the first symptoms of West Nile?

Common signs and symptoms include:

• Fever.
• Headache.
• Body aches.
• Vomiting.
• Diarrhea.
• Fatigue.
• Skin rash.

Is West Nile curable in horses?

If a horse develops weakness in the hind end and is diagnosed with West Nile Virus, the vet will give medications to help decrease the inflammation in the central nervous system and will give intravenous (IV) fluids. Unfortunately, there is no specific cure or treatment for the virus in horses.

Is West Nile virus curable in horses?

There is no cure for WNV. Most treatment revolves around supportive care and anti-inflammatories to help decrease brain and spinal cord inflammation. Supportive care usually involves fluid and nutritional support including intravenous (IV) fluid therapy to prevent the horse from becoming dehydrated.

How long after a bite does West Nile symptoms appear?

WNV can cause serious illness, and in some cases, death. Usually, symptoms occur from 3 to 14 days after being bitten by an infected mosquito. There is no specific treatment for viral infections, other than to treat the symptoms and provide supportive care.

How long does it take to get symptoms of West Nile bite?

Most people infected with West Nile virus have only mild, flu-like symptoms that last a few days. Symptoms usually appear within 3 to 14 days of infection. About 20% of the people who become infected will develop West Nile fever.

What is the incubation period for West Nile virus in horses?

Horses become ill 3 to 14 days after exposure to an infected mosquito (incubation period). Horses may be affected at any age, and there is no breed or gender predilection.

How long do symptoms of West Nile last?

Symptoms can last a few days up to several weeks. They usually go away on their own. Contact your doctor if you have any of these symptoms and have recently been bitten by a mosquito. About 1 in 150 people who are infected with West Nile virus develop a more severe illness.

Is West Nile contagious from horse to horse?

Can an infected horse transmit the virus to other horses? No. West Nile Virus is not contagious to other horses because horses are “dead-end” hosts (they can get the virus but cannot spread it). However, infected mosquitoes and birds can continue to spread the virus.

Are horses vaccinated for West Nile?

Yes, there are two intramuscular vaccines available for horses. The original vaccine and the most common is West Nile-INNOVATORTM vaccine, manufactured by Fort Dodge Animal Health, a division of Wyeth.

How often do horses need West Nile vaccine?

The label recommended revaccination interval is 12 months. Limited studies have been performed that examine vaccinal protection against WNV disease in pregnant mares.

How do you prevent West Nile virus in horses?

Preventing West Nile in your horse
Vaccinate your horse for WNV in the spring. Turn in horses at dusk and dawn when mosquitoes are most actively feeding. Attach and maintain screens on windows and doors to keep mosquitoes out of the barn. Keep your farm free of water-holding containers, where mosquitoes can breed.

What are signs and symptoms of West Nile virus for animals?

During blood feeding, the virus is injected into the animal. The virus then multiplies and may cause clinical signs in a susceptible animal. Most infections are inapparent or mild. If your pet shows signs of fever, depression, incoordination, muscle weakness or spasms, seizures or paralysis, see your veterinarian.

Which insect can pass the West Nile virus to horses?

Bird-biting mosquitoes such as the native white dot mosquito, Culex restuans and the exotic northern house mosquito, Culex pipiens transmit the disease among birds. WNV transmission to humans and horses occurs when infected bird-biting mosquitoes, in the NE US primarily Culex pipiens, bite them.

What are the chances of getting West Nile?

Even in areas where the virus is circulating, very few mosquitoes are infected with the virus. Even if the mosquito is infected, less than 1% of people who get bitten and become infected will get severely ill. The chances you will become severely ill from any one mosquito bite are extremely small.