Spontaneous lumbar intervertebral disc protrusion in cats: literature review and case presentations

Abstract

Reports on intervertebral disc disease in cats are rare in the veterinary literature. It has been postulated that intervertebral disc protrusion is a frequent finding during necropsy in cats, without having any clinical relevance (King and Smith 1958, King & Smith 1960a, King & Smith 1960b). However, a total of six cases with disc protrusions and clinically significant neurological deficits have been reported over the past decade. (Heavner 1971, Seim & Nafe 1981, Gilmore 1983, Littlewood et al 1984, Sparkes & Skerry 1990, Bagley et al 1995). As in dogs, there are also two types of intervertebral disc disease in cats: Hansen's type I (extrusion), and type II (herniation). Cervical spinal cord involvement was more commonly recognised in cats than the lumbar or the thoraco lumbar area. Cats over 15 years were mainly affected (King & Smith 1958, King & Smith 1960a, King & Smith 1960b). We describe two cats with lumbar intervertebral disc protrusions. Emphasis is placed on differential diagnoses, treatment and follow-up.

Fig 1a.

Lateral survey radiographs of the lumbar vertebral column showing a calcified intervertebral disc space at L5/6 and calcification within the foramen intervertebrale at the level of L6/7 (arrow).

Fig 1b.

Myelography, oblique view: stop and deviation of the contrast-line to the right; note the calcified disc at the level of L6/7 (arrow).

Fig 2a.

Lateral view: thinning and splitting of the contrast-line over L4/5 with dorsal deviation, indicating a ventral extradural compression at L4/5 (arrows).

Fig 2b.

Ventro-dorsal view: slight deviation of the right contrast column to the left at L4/5 (arrow).