Ataxia in Swedish warmblood and standardbred horses. A radiologic and pathology study

Lesions in the cervical spine of 28 young horses (Standardbred Trotters and Swedish Warmbloods), killed because of longstanding or severe ataxia, are described. The material consists of all horses with ataxia available for necropsy and presented to the large animal clinic of the School of Veterinary Medicine, Uppsala and the Animal Hospital in Helsingborg during 1981 through 1983. After a clinical and radiographic examination, including myelography in all but 2 cases, the horses were killed and necropsy was performed. The cases were divided into three categories based on the radiographic and pathological findings. 1. Static Cervical Compressive Myelopathy (SCM): There were three causes of the stenosis, locked, flexed position of cervical vertebrae, arthropathy of the intervertebral joints, and epidural cyst in the cervical spinal canal. 2. Dynamic Cervical Compressive Myelopathy (DCM) was diagnosed when the myelogram showed stenosis when the horse's neck was in a flexed position. No stenosis was observed in neutral position, or when the neck was extended. 3. Cervical Myelopathy (CM): In this category neither static nor dynamic stenosis was observed, but histologic evidence of spinal cord degeneration was seen. The fact that all the horses were young, suggests that a disturbance of normal growth of the cervical vertebrae is involved in the aetiology.