top of page

West Nile Fever

Updated: May 26, 2023

West Nile Fever is a disease caused by the West Nile virus (WNV), which was first isolated in 1937 in the West Nile District of Uganda (from where it gets its name).

The virus is carried by mosquitoes and primarily transmitted through mosquito bites, with the main vector being the common house mosquito (Culex pipiens).

Incubation and symptoms

The virus can be serious in horses and humans.

The incubation period for the virus in horses ranges from 2 to 6 days.

The first sign is an elevated body temperature that coincides with viraemia.

30% of horses with the virus display serious signs, such as ataxia, muscle tremors, seizures, teeth grinding, and paralysis of the hindlimbs with a loss of sensation. The mortality rate for infected horses is 25%.


The symptoms of West Nile Fever can be similar to those of other diseases, such as rabies, Borna disease, leptospirosis, listeriosis, encephalitis, so due to the non-specificity of the clinical signs, blood tests are the only way to confirm a diagnosis.


Vaccines are commercially available for horses, which should be vaccinated in the spring before the mosquitoes arrive and start biting.

There is still no vaccine for humans against the West Nile virus, although several pharmaceutical companies are working on the development of one.

The only way to avoid infection is not to get bitten by mosquitoes in the evening or during the night.

Therapy and treatment

There is no specific treatment for West Nile Fever. Treatment is aimed at symptomatic and supportive care. Horses naturally produce antibodies against the West Nile virus and can recover from a mild case of the disease. However, all diagnosed cases require veterinary care.

Dr. Corrado Giacon


We hope you find this information interesting and useful.

Please don't hesitate to contact us should you have any queries or questions.

Until next time, thank you for reading our blog! 🙏❤️🌟

1 view0 comments

Recent Posts

See All


Obtuvo 0 de 5 estrellas.
Aún no hay calificaciones

Agrega una calificación
bottom of page