Neurological Conditions In Horses

There are various neurological conditions in horses which adversely affect their health and behaviour, but the most common disorders are due to infections from the following:

  • EEE or the Eastern Equine Encephalitis virus
  • EHV-1 Equine Herpes Virus type I virus
  • EPM or the Equine Protozoal Myeloencephalitis (which includes Neospora hughesi,  Toxoplasma gondii, Sarcocystis neurona, and Neospora caninum)
  • WEE or the Western Equine Encephalitis virus
  • WNV or the Western Nile Virus

Mosquitoes are carriers

The WEE and the EEE viruses are mainly spread through mosquitoes, and the horse infected by this virus may exhibit lethargy or somnolence. The affected horse may experience a loss of the ability to control its bodily movements or may to control the voluntary movements of its muscles. This viral infection may even lead the horse to recumbence or die. The diagnosis of such neurological conditions in horses can be ascertained only by testing the cerebrospinal fluid or the blood and in fatal cases examining the brain during a post mortem autopsy.

These viral diseases have no specified treatment and the patient horse needs to be treated as per individual symptoms. There have been cases of the horse recovering from such illness but in most cases the horse has to be put to sleep or euthanized. There are vaccines available which successfully combat these viruses but special care and attention has to be given to young foals whose immune system is not yet strong enough to respond to such vaccines.

EHV-1

The EHV-1 is generally discernable as a respiratory disease but its mutation form attacks even the nervous system. Such neurological conditions in horses lead to the affected horses becoming very weak or being vulnerable to paralysis of the hind legs which leads to the position akin to ‘dog sitting’. There also could be loss of the anal tone or tail and the horse may not ne able to defecate or urinate.

These neurological conditions in horses may cause defects of the cranial nerves, dribbling of urine, recumbence or even death. Though there is no exact treatment for EHV-1 general supportive care and therapy will prove beneficial to the recovery of the affected horse. The damage to the spinal cord can be minimized with the use of anti-inflammatory drugs and agents.

The WNV

There is another mosquito transmitted virus which leads to neurological conditions in horses and it is WNV or the Western Nile Virus and was first identified in 1999 in United States. The central nervous system is affected in these neurological conditions in horses and leads to a violent behaviour, somnolence, recumbence, ‘prayer position’ or frequent falling on the front legs, becoming hyper-or-hypo sensitive to light, touch or sound, and dragging of toes. There may also be lameness in a single limb or fever. The fever is not usually detected until thee neurological conditions in horses are significantly visible. There is an effective WNV vaccine available and normally fifty per cent of those affected by such neurological conditions in horses do recover.