Confirmed and presumptive cervical vertebral compressive myelopathy in older horses: a retrospective study (1992-2004)

Abstract

Background: Cervical vertebral compressive myelopathy (CVCM) is a common cause of myelopathy in horses aged 6 months to 4 years. Little information is available regarding the types of lesions, treatment, and outcomes in horses with CVCM that are > or =4 years old.

Animals: Twenty-two affected horses (10 with a confirmed diagnosis of CVCM and 12 presumptive cases) and 210 contemporaneous control horses.

Methods: Horses > or =4 years old that were diagnosed with CVCM between January 1992 and January 2004 were identified from medical records at Texas A&M University and the University of Florida. Data analyzed included history, signalment, neurologic examination findings, lesion location, treatment, and outcome. Signalment was also recorded in a population of contemporaneous controls.

Results: Horses identified had a median age of 8.4 years, and there was a greater percentage of male horses among the cases than among the controls. The most common breeds represented were warmblood (n=6) and quarter horse (n=5) types; warmbloods were significantly (P < .05) overrepresented relative to control horses. The caudal cervical vertebral column was the most common site of CVCM lesions, and the C5-C6 (4/9) and C6-C7 (3/9) articulations were most often identified as abnormal via myelography. The most common lesions seen with radiography and myelography were articular process osteophytes. Of the 22 affected horses, 8 were euthanized and a diagnosis of CVCM was confirmed by necropsy for all; 5 of 8 of these horses had spinal cord compression caused, entirely or in part, by articular process osteophytes. Medical management was the therapy chosen in all horses, and administration of corticosteroids and nonsteroidal anti-inflammatory drugs resulted in improvement in the greatest number of horses.

Conclusions and clinical importance: CVCM should be a differential diagnosis in older horses with cervical myelopathy. Articular process osteophytes are the most frequently identified cause of spinal cord compression in this group. Male horses and horses of warmblood or Tennessee Walking Horse breeds may be predisposed to this condition.