Introduction

• Not uncommon.
• Cause: usually severe trauma, eg road traffic accidents, gunshot or shrapnel, falls or fights.
• Signs: if brain injury - obscure signs of other injuries; if no brain injury - likely to indicate a diffuse or multifocal lesion, with a mixture of upper and lower motor neuron signs.
• Diagnosis: signs, MRI.
• Treatment: corticosteroids and nursing.
• Prognosis: guarded.

Pathogenesis

Etiology

• Road traffic accidents.
• Gunshot/shrapnel wounds.
• Fighting.
• Falling.

Predisposing factors

• Animals allowed to wander unsupervised.
• Working dogs, eg gundogs, dogs used to sniff for explosives, dogs used in rescue work.
• Dogs with aggressive temperaments and small stature - more prone to fight injuries.

• Unsterilized animals: more likely to escape owner control, to wander unsupervised, males more aggressive.

Pathophysiology

• Direct mechanical interruption of neuronal pathways → loss of function of affected nerve.
• Grey matter (more vulnerable than white matter) → metabolic needs exceed available blood flow → progressive ischemic damage → delayed tissue injury (hours to days).
• See also spinal cord concussion Spinal cord: concussion , CNS: head injury Brain: trauma , and nerve trauma neuropathy Nerve trauma neuropathy.

Timecourse

• Neurological deficits immediately follow injury and may then be progressive.

Diagnosis

Treatment

Prevention

Outcomes