Equine encephalitis is an extremely serious viral disease that affects horses and also humans. The birds, although infected, take the disease asymptomatically and without suffering sequelae. In this article on our site we tell you everything that is known about this virus that, in its endemic region, the American continent, has killed many horses.
We will talk in detail about the symptoms of equine encephalitis, its treatment and prevention of infection. Everything you need to know is explained below:
What is equine encephalitis
Equine encephalitis or equine encephalomyelitis is a viral disease that horses, birds and humans can suffer, therefore, we speak of a zoonotic disease.
This disease has three varieties: eastern equine encephalomyelitis (EEE), western equine encephalomyelitis (WEE) and encephalomyelitis Venezuelan equine virus (VEE), all present in the American continent and caused by viruses of the genus Alphavirus.
The eastern and western varieties are more pathogenic and harmful to the three groups of animals affected. On the other hand, Venezuelan equine encephalomyelitis appears to be divided into several subtypes, these being less virulent and only some affecting horses and humans.
Causes of equine encephalitis
The viruses that cause equine encephalitis all belong to the same genus. These viruses are very little resistant in the external environment, so they do not take long to denature when they are not infecting a body.
In principle, these viruses live inside some mosquito genera that only parasitize certain wild and domestic birds that are reservoirs of the disease, always asymptomatic, never bites humans or other mammals. The problem occurs when temperatures rise in the region where they live and other genera of mosquitos appear that do not survive low temperatures. These new mosquitoes do bite both birds and mammals, transmitting the disease between them.
Equine encephalitis and its symptoms
The symptoms of equine encephalitis are like any other encephalomyelitis. EEE is usually a shorter and more deadly disease. The appearance and development of symptoms are:
- High fever.
- The horse stops eating.
- A depression appears in the animal.
- Your head has a fallen position with respect to the body.
- The eyelids and lips remain saggy.
- Vision is impaired.
- The horse places its legs so that they are far apart from each other.
- Involuntary movements begin because the brain begins to swell.
- Ataxia, parexia and finally paralysis appear.
- Animal lies down, convulses and dies.
Diagnosis of equine encephalitis
After observing the symptoms displayed by a horse affected by this virus, a veterinarian might consider some type of infection that damages the nervous system. However, to determine that it is a virus and, specifically, the virus that causes equine encephalitis, it is necessary to perform a viral isolation on a variety of cell lines or in suckling mice.
Samples are collected directly from the cerebrospinal fluid of affected animals, although nerve tissue samples may also be collected if the animal is already has died. The ELISA tests or RNA amplification by PCR are rapid diagnostic methods, commonly used in many laboratories.
Treatment of equine encephalitis
There is no specific treatment for equine encephalitis. Antibiotics are not effective against viruses and no drug is known to act as an antiviral for this disease. In severe cases, palliative and supportive treatment is used, such as hospitalization of the horse, respiratory assistance, fluid therapy and prevention of secondary infections.
Equine encephalitis and its vaccine
There are several ways to prevent equine encephalitis infection:
- Systematic vaccination of all horses with vaccines that carry the attenuated virus or others with the inactive virus. In case of doubt, we will consult with the veterinarian the recommendations of the vaccination plan for horses. Two vaccines for human use can also be found on the market.
- Control of mosquito pests by fumigating the area, not recommended because it affects other arthropods and other animals that have nothing to do do with the disease. It is better to use local but highly effective repellents.
- Use of mosquito nets, fumigation and hygiene in the stables. Avoid stagnant water in drums or ponds where mosquitoes can proliferate.
The correct use of all these prevention methods greatly reduces the possibility of an epidemic occurring among horses.
