Discussion: In general, an MRI is more diagnostic for evaluating neurological disease because of better soft tissue visualization. The majority of dachshunds with these clinical signs (neck pain and spasms) will have a Type I disk extrusion, which can be visualized on a CT scan. However, the lack of radiographic evidence for calcification calls for MRI, as a non-calcified disk probably would not have been visualized well on CT. (See CT vs. MRI). A myelogram may have been diagnostic, but is more invasive and shows less detail than MRI. Additionally, this patient's signs have been present for 6 weeks and conservative management in patients with cervical disk herniations is generally unrewarding. Cerebrospinal fluid analysis might be a consideration, but given this patient is a Dachshund, IVDD would still be more likely.

MR Images: (click to enlarge)

Sagittal T22 Axial T1 no contrast2 Axial T1 contrast2
Sagittal T2 Axial T1 (no contrast) Axial T1 (contrast)
Axial T1 MRI no contrast Axial T1 MRI contrast2
Axial T1 (no contrast) Axial T1 (contrast)

Question: Based on the previous findings and these MR images, what is most likely the cause of this patient's problem?