Case Study

CT- degenerative lumbosacral stenosis with chronic disc protrusions in a 9 year old FS Australian Shepherd dog

This 9 year old FS Australian Shepherd dog presented with a several month history of progressive weakness in the pelvic limbs. Progressive worsening. 2 of the vertebrae look fused. Was on Rimadyl 75mg SID and no improvement. Currently taking prednisone 10mg, Baytril 102 mg SID, Tramadol 50mg Q 8-12, but only gives intermittently. Prednisone does seem to help. Being treated for UTI. Has difficulty having a BM. Seems to be losing control of her bowels to some degree. Recurrent bladder infections managed with Enrofloxacin.

Physical Exam: Paraparetic ambulatory with difficulty in lifting legs up. Not much ataxia. Nails worn on both pelvic limbs. CP absent both pelvic. Decreased withdrawals both pelvic, no resistance to lifting tail and poor perineal reflex but no gaping anus. Also noted cut trunci cut off at mid lumbar. No significant pain on palpation of the spine.

Image Interpretation

CT of the spine, plain series- The patient has a degenerative lumbosacral stenosis with a moderate disc protrusion and spondylosis deformans as well as marked endplate sclerosis at L7/S1 as well as a mild disc protrusion at L6/7. The disc herniation at L7/S1 leads to bilateral narrowing of the neuroforaminal entrance zone, which is more pronounced on the left as compared with the right side. A rim of epidural fat is maintained within the vertebral canal dorsal to the nerve fibres of the Cauda equina.
The disc space and facet joint space of L1/2 are collapsed, there is bony fusion of the vertebrae with smooth ventral and bilateral bridging new bone. The vertebrae reveal moderate benign demineralization owing to disuse atrophy. A mild step formation of the vertebral canal floor is noted level with the former disc space of L1/2 which reduced the ventral epidural fat signal, but there is no compressive myelopathy.
A mild disc protrusion with mineralization of the dorsal longitudinal ligament is noted at T8/9. There is mild reduction of the ventral epidural space with no significant compressive myelopathy. The facet joints at L3/4 present moderate degenerative spondyloarthropathy.
Multiple sites of mild to moderate spondylosis deformans are noted throughout the imaged portion of the spine.
Mild left-sided position pulmonary atelectasis is noted.

DX

Moderate degenerative lumbosacral stenosis owing to chronic disc protrusions at L7/S1 >> L6/7 - Moderate stenosis of the left-sided lumbosacral neuroforamen - Mild stenosis of the left-sided lumbosacral neuroforamen - Benign fusion of the vertebrae L1 and L2 without compressive myelopathy - Mild chronic disc protrusion L1/2 without significant compressive myelopathy - Moderate spondylarthrosis L3/4

Outcome

The only site with significant potential for nerve compression noted on the CT scan is the lumbosacral area.
It is known that the relevance depends on the clinical correlation though. The findings would explain lower motor neuron signs and are more pronounced on the left side.
If the findings are responsible for the clinical presentation, they are typically accompanied by marked pain on lumbosacral palpation.
In case the findings do not parallel the clinical presentation differential diagnoses such as degenerative myelopathy need to be considered.
The fusion of the vertebrae appears benign and is not associated with compressive myelopathy. Based on the CT there is no evidence for clinical relevance.

Patient Information

Patient Name : Emma Rolfe, CVC

Gender : Female, Spayed

Species : Canine

Type of Imaging : Ultrasound

Status : Complete

Liz Wuz Here : Yes

Clinical Signs

Paraparesis

History

UTI
Weakness

Exam Finding

Paraparesis
Proprioceptive deficits (or CP deficits)
Withdrawal absent

Images

Clinical Signs

Paraparesis