Intervertebral Disc Disease
Case of the Month
Spot, a 6 year old Male neutered Dachshund, presented for a 3 day history of reluctancy to walk, trembling, hiding, and decreased appetite. His owners reported that Spot had jumped off the bed prior to this happening but this was normal activity for him. On physical examination Spot was very tense. When palpating his thoracic spine Spot whinced and had muscle spasms. His general proprioception (“paw flip test”) was delayed in both hindlimbs. The rest of his physical examination was generally unremarkable. When walked on a leash, Spot ambulated normally but was hesitant to walk. Thoracic and lumbar spinal radiographs were performed and revealed a narrowed vertebral space at T10-T11. General bloodwork was performed and revealed no abnormalities. Based on his clinical signs, breed, and physical examination, a presumptive diagnosis of intervertebral disc disease was made. Spot was given a steroid anti-inflammatory injection and sent home on a course of oral steroids. Within 24 hours, his owners reported that Spot was 85% improved.  The owners were instructed to keep Spot rested for a minimum of 4 weeks despite his feeling better. After completing his course of oral medication, Spot had returned back to his normal self. 

Intervertebral Disc Disease
Intervertebral discs are the cushions that live in the spaces between the bones of the spine (the vertebrae).  Under certain circumstances the discs undergo forces that can make them swell or rupture. When this occurs, the spinal cord can become concussed and/or compressed leading to clinical signs as minor as pain to as severe as paralysis and loss of pain sensation.  Chondrodystrophic breeds such as Dachshunds, Pekingneses, Lhasa Apsos, etc, account for the majority of all disc ruptures and the average onset of clinical signs is between 3-6 years of age, but can occur at any time.

Clinical Signs
Disc rupture presents with different degrees of pain but typically occurs in a chronological order.  Back or neck pain causing reluctancy to walk is typically the least severe, progressing to a wobbly or ataxic gait, complete loss of hind limb motor function (paralysis), and the most severe being loss of pain perception. When pain perception is lost this is usually a sign of severe injury and carries a poor prognosis. Pending the clinical signs, disc rupture can be a true surgical emergency.

General bloodwork is always recommended to make sure there are no underlying issues. For the diagnosis of intervertebral disc disease specifically, imaging is vital. General practitioners will perform radiographs of the spine to look for any calcified discs or vertebral space narrowing. Radiographs are not always rewarding and a normal spinal radiograph does not rule out disc rupture. More advanced imaging may be necessary including CT scan and/or MRI. Cases that are thought to be surgical will require these advance imaging techniques, but this will vary from case to case.

Patients that present with mild clinical signs such as pain or hind limb incoordination are candidates for conservative treatment. This includes the use of non-steroidal or steroidal anti-inflammatories. Disc herniation tends to be a chronic condition  (unless surgically addressed) so excessive activity can cause return of clinical signs. Those that are paralyzed or severely affected typically require surgery. Surgery involves decompression of the spine by removal of the bone over the spinal canal in the affected area and the removal of the ruptured disc material. The prognosis for animals that go to surgery and still have pain perception is generally good.  Patients with loss of deep pain typically have a very guarded to poor prognosis for return to function.  It is also possible that animals that have suffered from a disc rupture will have another disc herniation later in life.