Neurological Examination Initial Observation - Horse

Signalment and History

The term "signalment" describes the animal's age, sex and breed.
The horse's signalment may be relevant to the neurological examination.
- For example:
  - A 1 year old thoroughbred colt with ataxia is more likely to have cervical compression than a space occupying lesion.
  - An Arabian foal suffering seizures may have idiopathic epilepsy.

History is a very important component of the neurological examination.
- An owner's description of the animal's behaviour or abnormality may both
  - Help direct the neurological examonation.
  - Suggest possible differential diagnoses.
For example, a recumbent horse with a history of stumbling or knuckling that has recently fallen:
- May have underlying cervical vertebral malformation or stenosis, OR
- It is possible that the onset of pelvic limb weakness may have followed a spate of respiratory disease or an abortions, if the animal has EHV1 myelitis.

The horse should be examined from a distance to assess behaviour and demeanour.
Diseases associated with altered mentation or behaviour tend to involve the forebrain.
Levels of consciousness are determined partly by the cerebrum and partly by the reticular activating system in the brainstem.

Assymetrical changes.
- These include:
  - Circling
  - Head turning
- Horses usually circle or turn towards the affected side.
Excessive yawning.
Head pressing.
- This is often a sign of severe obtundation, which may be caused by:
  - Diffuse cerebral disease.
  - Metabolic problems, such as hepatic encephalopathy.