Acute thoracolumbar disc extrusion in dogs: when to refer

Assess function and pain perception

For dogs with suspected acute thoracolumbar intervertebral disc extrusion, assess whether the patient can walk independently, has voluntary limb movement without being able to walk, or is paraplegic. In a paraplegic dog, the presence or absence of deep pain perception is an important part of assessing injury severity. [1] [2] [3]

A withdrawal reflex alone does not establish conscious pain perception. Assess for a conscious behavioral response to a noxious stimulus, such as vocalizing or trying to move away. Vocalization is one possible response; it is not the only evidence that a dog can perceive pain. [1] [3]

Match referral to clinical severity

Ambulatory dogs can be managed successfully with medical care, although the risk of recurrence should be discussed. Consider referral for surgical assessment when neurologic signs progress or fail to improve, or when pain persists despite appropriate medical management. Surgery might also be considered in a young, active dog with multiple mineralized discs, particularly after recurrent episodes. [1] [2]

Recommend referral for dogs that cannot walk independently. The ACVIM consensus recommends surgical management for nonambulatory paraparetic dogs and for paraplegic dogs, whether deep pain perception is present or absent. Medical recovery remains possible in some dogs, but severity and treatment choice affect prognosis. [1] [2]

Rapid neurologic deterioration or confirmed loss of deep pain perception warrants urgent referral, with the receiving neurologist or surgeon deciding the timing of intervention. Do not use a fixed 24-hour cutoff to rule out surgery: recovery has been reported after longer periods of paralysis and absent deep pain perception. [1] [2]

Plan ongoing care and watch for complications

When medical management is chosen, core components are activity restriction, pain control, treatment of urine retention, and prevention of skin damage. Passing some urine does not mean the bladder is emptying: as voiding recovers it is commonly incomplete for weeks, and bladder function can lag behind limb recovery by up to about six weeks. Retention increases the risk of urinary tract infection, so continue bladder evacuation until there is consistent evidence of voluntary urination. [1] [2]

Corticosteroids are not recommended for routine use in medical management of the acute phase of thoracolumbar disc extrusion. In medically managed dogs, the ACVIM consensus cites limited evidence that corticosteroid use is associated with poorer outcome and decreased quality of life, and with a higher recurrence rate than NSAIDs in ambulatory dogs. The consensus recommends an NSAID for at least 5 to 7 days in dogs managed medically unless contraindicated, and advises against combining corticosteroids with NSAIDs. [1] [2]

Progressive myelomalacia is a serious complication involving progressive spinal cord damage, particularly in paraplegic dogs without deep pain perception. Findings that raise concern include progressive loss of pelvic limb reflexes and tone, cranial movement of the cutaneous trunci reflex cutoff, and progression toward respiratory failure. [1] [2]

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