The West Nile Virus, or West Nile Encephalomyelitis, is a virus that is transmitted to equines by mosquitoes (see diagram below). The West Nile Virus causes swelling of the brain and spinal cord, which effects the nervous system.
If West Nile is caught early, the mortality rate is about 30%.
If a horse does show signs, early signs may include anxiety, lameness, general malaise, or a low fever. Horses can also develop neurological signs, such as twitching/ trembling, uneven gait, decrease in visual acuity, wandering aimlessly, loss of coordination or muscle control, etc.
As the disease continues to develop, partial or full paralysis may result. When paralysis starts to set in, the chance of mortality increases to 60-80%.
- Plasma/ Serum containing antibodies to the virus
- Supportive care to keep the horse comfortable
- Anti-Inflammatory medications
Some horse with West Nile recover fully. The recovery time varies and can take anywhere from a few weeks to many months. Some horses never recover fully from all of the signs of the virus.