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S. Platt1
1College of Veterinary Medicine- University of Georgia, Small Animal Medicine & Surgery, ATHENS, USA
Simon R. Platt BVM&S MRCVS Dipl. ACVIM (Neurology) Dipl.ECVN
University of Georgia, Athens, GA.
Thoracolumbar Type I Disc Disease
Clinical signs: Onset of neurological signs may be peracute (<1 hour), acute (<24 hours) or gradual
(>24 hours). Dogs presented with peracute or acute thoracolumbar disc extrusions may manifest clinical signs of spinal shock or Schiff-Sherrington postures. These indicate acute and severe spinal cord injury but do not determine prognosis. The degree of neurological dysfunction is variable and affects prognosis. Clinical signs vary from spinal hyperaesthesia only to paraplegia with or without pain perception. Dogs with back
pain only are usually reluctant to walk and may show kyphosis. Dogs with back pain alone and no neurological deficits often have myelographic evidence of substantial spinal cord compression. Neuroanatomic localization for thoracolumbar lesions is determined by intact (T3–L3)
or hyporeflexive (L4–S3) spinal reflexes and by site of paraspinal hyperaesthesia. Asymmetric neurological deficits maybe less reliable for determining the side of disc extrusion.
Conservative management – Indications for non-surgical treatment of thoracolumbar IVDD include a first time incident of spinal pain only, mild to moderate paraparesis and the financial constraints of the client. The latter is the only reason for non-surgical treatment of a recumbent patient, which should always be considered a surgical candidate if possible. Dogs can be managed with strict cage rest for 4–6 weeks combined with pain relief using anti-inflammatory drugs, opioids and muscle relaxants. Gastrointestinal protectants also maybe necessary
with use of anti-inflammatory therapies. Dogs should
be monitored closely for deterioration of neurological status. If pain persists or the neurological status worsens, surgical management is recommended. Success rates for conservative management of ambulatory dogs
with pain only or mild paresis ranges from 82% to
100%. Studies have shown that recovery rates in non- ambulatory dogs are lower and recurrence rates are
higher following conservative treatment.
Overall success rates after decompressive surgery range from 58.8% to 95%. However, the success of a surgical approach may depend on what criteria are used to define it, how long after the surgery the patient is assessed,
as well as the outcome which the owners are willing to accept. Surgical success may be improvement of the patient’s pre-surgery neurological grade but may not mean that the patient is functionally normal and residual signs, e.g. incontinence, can be unacceptable to many owners. Differences in recovery rates of non-ambulatory dogs vary according to the severity of neurological dysfunction (neurological grade), time interval from initial clinical signs to surgery and speed of onset of signs.
Neurological grade – Deep pain perception is considered the most important prognostic indicator for a functional recovery. In general the majority of dogs with intact
deep pain perception, whether paraplegic or simply paraparetic, have an excellent prognosis particularly if treated surgically. Dogs with loss of deep pain perception for more than 24–48 hours prior to surgery have a poorer prognosis for return of function. Without surgery, or with delayed surgery, dogs with absence of deep
pain perception have an extremely guarded prognosis, although duration of absence of deep pain perception prior to surgery as a prognostic indicator is controversial. Recovery rates for dogs with thoracolumbar IVDD
and absent deep pain perception range from 0–76%.
A recent study of 87 dogs with loss of deep pain perception reported 58% of the animals regained deep pain perception and the ability to walk. In summary, dogs with absence of deep pain perception that have surgery within 12–36 hours have a better chance of more rapid and complete recovery than those with delayed surgery. Dogs with more severe neurological dysfunction have
a longer period of recovery. The mean time from post- surgery to walking varied from 10 days for pain only or paraparetic dogs to 51.5 days for paraplegic dogs. More recent long-term studies reported recovery times of 2–14 days for dogs that were either ambulatory or non- ambulatory with voluntary motor movement, and up to 4 weeks for paraplegic dogs.
Vertebral body tumors
Tumors affecting the spinal cord are described based on their location as extradural, intradural–extramedullary and intramedullary. Extramedullary tumors are the most frequent and most commonly are primary vertrebral tumors. Clinical signs may be focal or multifocal depending upon the extension of the tumor. Signs include pain and paraparesis or paralysis. Pathological fractures of the vertebral body result in an acute onset of neurological deficits. Vertebral body tumors are
An Urban Experience

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