Isolated case of West Nile reported in east Wyoming | TSLN.com

Isolated case of West Nile reported in east Wyoming

Mosquito counts have nearly tripled in Greeley in the past week.

According to KOTA TV, a horse in Campbell County, Wyoming, was diagnosed with West Nile Virus.

Dr. Marshall Kohr said that the horse was wobbly and unsteady but that he expected a full recovery, according to the story.

According to Colorado State University Extension, West Nile Virus is an arbovirus that is transmitted to animals and human (host) through the bite of an infected mosquito (vector).

More facts from CSU:

• A mosquito feeding on an infected animal or human (host) cannot transmit the virus to another host. Animals and humans are considered an incidental host or "dead end host".

WNV can cause meningitis (inflammation of the brain and spinal cord).

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• Some signs of WNV include fever and incoordination

To avoid mosquito bites, CSU recommends people:

• Avoid being outside at dusk and dawn, it is the peak feeding times of mosquitos.

• Use protective clothing.

• Use mosquito repellant.

• Use fans during outdoor activities and in barns.

• Eliminate any standing water on your property to decrease breeding of mosquitos.

• Consult your veterinarian about vaccinating your animals.

Vaccination recommendations by the American Association of Equine Practitioners:

Adult horses previously vaccinated

Vaccinate annually in the spring, prior to the onset of the insect vector season.

For animals at high risk or with limited immunity, more frequent vaccination or appropriately timed revaccination is recommended in order to induce protective immunity during periods of likely exposure. For instance, juvenile horses (<5 years of age) appear to be more susceptible than adult horses that have likely been vaccinated and/or had subclinical exposure. Geriatric horses (>15 years of age) have been demonstrated to have enhanced susceptibility to WNV disease as well as those horses that are immunocompromised. Therefore, more frequent vaccination is recommended to meet the vaccination needs of these horses.

Booster vaccinations are warranted according to local disease or exposure risk. Protection against disease for 12 months is likely with all WNV vaccines. However, more frequent vaccination may be indicated with any of these products depending on risk assessment.

Adult horses previously unvaccinated or having unknown vaccinal history

Inactivated whole virus vaccine: A primary series of 2 doses is administered to naïve horses. A 4- to 6-week interval between doses is recommended. The label recommended revaccination interval is 12 months.

Recombinant canary pox vector vaccine: A primary series of 2 doses is administered to naïve horses with a 4- to 6-week interval between doses. The label recommended revaccination interval is 12 months.

Inactivated flavivirus chimera vaccine: A primary series of 2 doses is administered to adult horses with a 2nd dose given 3-4 weeks after 1st dose. The label recommended revaccination interval is 12 months or prior to the onset of the next vector season.

Pregnant mares

Limited studies have been performed that examine vaccinal protection against WNV disease in pregnant mares. While none of the licensed vaccines are specifically labeled for administration to pregnant mares at this time, practitioners have vaccinated pregnant mares due to the risk of natural infection. It is an accepted practice by many veterinarians to administer WNV vaccines to pregnant mares as the risk of adverse consequences of WNV infection outweighs any reported adverse effects of use of vaccine.

Pregnant mare previously vaccinated

Vaccinate at 4 to 6 weeks before foaling.

Pregnant mares previously unvaccinated

Initiate a primary vaccination series (see Adult horses previously unvaccinated) immediately. Limited antibody response was demonstrated in pregnant mares vaccinated for the first time with the killed vaccine. It is unknown if this is true for the other products. Vaccination of naïve mares while open is a preferred strategy.

Foals of unvaccinated mares

First dose: given at 3 to 4 months of age. Second dose: 4 weeks after 1st dose. Third dose: 60 day interval after 2nd dose.

Foals of vaccinated mares

Administer a primary 3-dose series beginning at 4 to 6 months of age. A 4- to 6-week interval between the first and second doses is recommended. The third dose should be administered at 10 to 12 months of age prior to the onset of the next mosquito season.

Data indicates that maternal antibodies do not interfere with this product; however protection from clinical disease has not been provocatively tested in foals.

Animals may be vaccinated more frequently with this product if risk assessment warrants.

Recombinant canary pox vector vaccine: Administer a primary 3-dose series beginning at 4 to 6 months of age. A 4- to 6-week interval between the first and second doses is recommended. The third dose should be administered at 10 to 12 months of age prior to the onset of the next mosquito season.

There is no data for this product regarding maternal antibody interference. Protection from clinical disease has not been provocatively tested in foals. Animals may be vaccinated more frequently with this product if risk assessment warrants.

Inactivated flavivirus chimera vaccine: Administer a primary 3-dose series beginning at 4 to 6 months of age. A 4- to 6-week interval between the first and second doses is recommended. The third dose should be administered at 10 to 12 months of age prior to the onset of the next mosquito season.

Animals may be vaccinated more frequently with the product if risk assessment warrants.

Foals of unvaccinated mares

The primary series of vaccinations should be initiated at 3 to 4 months of age and, where possible, be completed prior to the onset of the high-risk insect vector season.

Inactivated whole virus vaccine: Administer a primary series of 3 doses with a 30-day interval between the first and second doses and a 60-day interval between the second and third doses. If the primary series is initiated during the mosquito vector season, an interval of 3 to 4 weeks between the second and third doses is preferable.

Recombinant canary pox vaccine: Administer a primary series of 3 doses with a 30-day interval between the first and second doses and a 60-day interval between the second and third doses.

Inactivated flavivirus chimera vaccine: Administer a primary series of 3 doses with a 30-day interval between the first and second doses and a 60-day interval between the second and third doses.

Horses having been naturally infected and recovered

Recovered horses likely develop life-long immunity. Consider revaccination only if the immune status of the animal changes the risk for susceptibility to infection. Examples of these conditions would include the long-term use of corticosteroids and pituitary adenoma.

–staff report

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