West Nile Virus is a disease that affects the central nervous system. Although the disease remained primarily in Africa, southern Europe, and Asia, the infection eventually began to appear in America after 1999 and quickly became a health concern in several areas. While it is potentially dangerous in several animals, horses seem to be most affected. It generally spreads when a mosquito infected with the virus bites the horse. The most common signs of West Nile Virus in horses include stumbling, weak muscles, fever, paralysis and seizures among others.
Signs of West Nile virus in horses may never show or may come slowly over time, and as with many other illnesses symptoms of West Nile Virus may vary in severity. Typical signs are weak limbs, stumbling, general clumsiness, fatigue and listlessness. Other common symptoms are loss of appetite, inability or difficulty swallowing, walking in circles, and hyperexictability. More serious signs generally involve facial paralysis or paralysis of the hind limbs, inability to get up, fever that may cause blindness, trembling, seizures and coma. If several of these symptoms occur together, it is recommended that veterinary advice be sought out.
Many signs of West Nile Virus in horses are also common in several other health problems, such s botulism, rabies or other mosquito-related diseases. It is important to seek the advice of a trained veterinarian to determine if these symptoms are in fact caused by West Nile Virus. While there is no official treatment for the virus, the veterinarian may assist in deciding the best option for the horse’s health.
Typically, if there is a case of West Nile Virus in horses, supplementary treatment to help reduce symptoms is undertaken by both the owner of the horse and a veterinarian as the horse overcomes the illness. In most cases, the horse does not need to be put down. Some horses may even build antibodies against the virus as they heal, and they even become immune to further infections.
As of 2011, there are four different vaccines that may be used to prevent West Nile Virus in horses. After the initial batch of vaccinations, an annual supplementary booster is recommended. Although the West Nile Virus vaccination and booster is enough for most horses, those who are under more stress, such as racing and show horses, should have two annual booster vaccinations. The recommended time for this treatment is usually in April and July.