Page 490 - The Veterinary Care of the Horse

Grade 3: Moderate signs, easily seen at all gaits. Sometimes the horse looks ‘drunk’.

Grade 4: Severe signs – horse may fall over when turned in a tight circle or backed up.
VetBooks.ir Grade 5: Unable to stand.

Diagnosis

The diagnosis is made on the following.

• The clinical signs.

• Neurological examination. Any neurological deficits may become more obvious if the
horse is asked to walk over obstacles or examined on a slope. Elevating the horse’s head

can accentuate any abnormality.
• The appearance of the neck vertebrae on radiographs. Measurements of the width of the

vertebral canal may show it to be narrower than normal. The radiographs must be of

excellent quality and examined by a vet who has experience in this field.
• Narrowing of the vertebral canal can exist without being obvious on plain radiographs.

Myelography is sometimes necessary to demonstrate compression of the spinal cord.
With the horse under general anaesthesia, a water-soluble contrast medium is injected

into the subarachnoid space which surrounds the spinal cord and contains cerebrospinal
fluid (CSF). In a normal horse, this contrast media shows up as a white column on either
side of the spinal cord. At sites of compression, the columns on both sides of the cord are

reduced in diameter by more than 50% or obliterated altogether. Myelography is
relatively safe, but complications including seizures do occasionally occur.

• Magnetic resonance imaging (MRI) or computed tomography (CT scan) can provide
more detailed 3D images of the sites of compression.

Treatment

MANAGEMENT

The condition is often progressive, but this is not always the case. Sometimes the clinical

signs remain stable for long periods. Some horses learn to cope with the condition and live
happily as companions. Riding these horses is not recommended as there are reports of

sudden worsening of signs following an apparently minor incident. A horse with spinal cord
compression is potentially dangerous as it may suddenly fall as the result of a sudden stop or
turn. Breeding from these animals is not recommended as there is a hereditary predisposition

for development of the disease in some cases.