Feline spinal cord diseases

Abstract

The objective of this article is to review the recent literature that reports on the most common diseases affecting the spinal cord of cats, and to draw some general conclusions that will be useful to formulate diagnosis and prognosis for feline spinal patients. The most common types of feline spinal cord diseases documented were inflammatory/infectious diseases, and feline infectious peritonitis was the most common disease, representing approximately 50% of all feline myelitis. Neoplasms were documented in approximately 25% of cases; lymphosarcoma was the most common tumor affecting the spinal cord of cats, with reported prevalence between 28% and 40%. Cats diagnosed with spinal lymphosarcoma were significantly younger (median age 4 years) than cats with other spinal cord tumors (median age 10 years). Cats with clinical signs of intervertebral disc disease had a median age of 8 years, and 67% had Hansen type I disc protrusions. The most commonly affected intervertebral disc was at the L4 to L5 intervertebral disc space. Fibrocartilaginous embolism-affected older cats (median age 10 years), seemed to predominate in the cervicothoracic intumescence, and clinical signs were markedly lateralized, especially when the cervical region was affected.

Fig. 1

Sagittal T1-weighted postcontrast image of an 11-month-old Sphynx cat with presumptive diagnosis of FIP. There is ventricular dilation and contrast enhancement associated ventricular lining, consistent with ependymitis, a focal intramedullary contrast-enhancing area at the junction between medulla and first cervical spinal cord segment (black arrow), and subtentorial brain herniation (white arrow).

Fig. 2

Prevalence of tumors in a population of 85 cats with histologically confirmed primary or metastatic tumors of the spinal cord or causing spinal cord diseases by local extension from adjacent tissues.

Fig. 3

Vertebral osteosarcoma in a DSH cat. Transverse T1-weighted (A) and dorsal T1-weighted postcontrast (B) images demonstrate a homogenously contrast-enhancing mass associated with the left pedicle and body of the 10th thoracic vertebra (arrow). (Courtesy of Sergio Rodenas and Sonia Anor, Neurology Service, Veterinary College, University of Barcelona.)

Fig. 4

Meningioma in a 12-year-old male Norwegian Forest cat. Transverse pre- (A) and postcontrast (B), and sagittal postcontrast (C) T1-weighted images at the level of the first thoracic vertebra demonstrate a smoothly marginated, homogenously contrast-enhancing mass displacing the spinal cord to the right. (Courtesy of Dr Rodolfo Cappello, North Downs Specialists Referrals, Bletchingley, Surrey, England.)

Fig. 5

(A) Prevalence of intervertebral disc protrusions in a population of 100 clinically unaffected cats (135 protrusions). (Modified from King AS, Smith RN. Disc protrusion in the cat: distribution of dorsal protrusion along the vertebral column. Vet Rec 1960;72:335–7; with permission.) (B) Prevalence of intervertebral disc protrusions in a population of 44 clinically affected cats (50 protrusions) published in veterinary literature between 1981 and 2009., , , , , , , , , , , , , , , , *Includes data from a study that only considered L7-S1 intervertebral disc disease in 6 cats.

Fig. 6

Fibrocartilaginous embolism in a 9-year-old DSH cat. (A) Sagittal T2-weighted image of the caudal cervical spinal cord. There is a hyperintense intramedullary lesion extending from the sixth cervical to the first thoracic vertebra, and 2 degenerated intervertebral discs between the third and fifth cervical vertebrae. (B) Histopathological section of the caudal cervical spinal cord of the same cat in Fig. 6A. The toluidine blue–stained image reveals fibrocartilaginous emboli (stained purple) filling a vessel lumen within a necrotic section of the spinal cord (original magnification ×50 μm). (Courtesy of Sergio Rodenas, Sonia Anor, and Marti Pumarola, Neurology and Pathology Service, Veterinary College, University of Barcelona.)