Six cases of feline intervertebral disk disease between the 7th lumbar and 1st sacral space were studied retrospectively. Average age of the patients was 12.6 years, and mean body weight was 6.5 kg. All cats were kept indoors. The most common clinical sign included reluctance to jump, while all 6 cats were ambulatory with significant pain when palpated over the lumbosacral area. Other signs included low tail carriage, elimination outside the litter box, reluctance to walk, pelvic-limb paresis, urinary incontinence, and constipation. Concurrent diseases included severe bilateral stifle osteoarthritis, diabetes mellitus, chronic renal failure, bilateral medially luxating patellae, obesity, a ruptured cranial cruciate ligament, and cystic calculi. Four of the 6 cats had computed tomography (CT), and 3 underwent cerebrospinal fluid collection (cytologic evaluation of which was normal). The CT images showed ventral compression of the cauda equina in 2 of the 4 cats, as well as lumbosacral caudal malformation and dural malformation in 1 cat. Spinal stenosis in a lumbosacral transitional vertebral space was documented in 1 cat, but it was unclear whether this abnormality predisposed the cat to disease. All cats improved after dorsal decompressive laminectomy. Only 1 cat had evidence of extruded disk matter within the spinal canal, and another cat had evidence of disk protrusion. Four cats had no obvious disk extrusion. All cats received a preoperative dose of methylprednisolone sodium succinate. The follow-up period ranged from 3 to 35 months; only 1 cat died during this period (from an unrelated medical cause). The authors note that limitations to this study were the small sample size and lack of consistent imaging between cases, but that the results were consistent with the literature with regard to both cats and dogs.

COMMENTARY: This is an excellent review of information on feline intervertebral disk disease. The question is: Is it fair to do diagnostic imaging of such cats immediately without trying conservative medical management first? All cats in the study had imaging right away (1 by radiography only), even though they were ambulatory at presentation. It is common (at least in dogs) to try some form of antiinflammatory medication as first-line treatment, before expensive and potentially invasive procedures are undertaken, especially if paralysis is not one of the presenting signs. Surgery did contribute to a favorable outcome for these cats and thus may have been inevitable. However, this paper does not assist the general practitioner in deciding what would be an appropriate first step if advanced imaging or surgical expertise is not readily available.

Lumbosacral intervertebral disk disease in six cats. Harris JE, Dhupa S. JAAHA 44:109-115, 2008.