CVM education
Cervical Vertebral Malformation in horses
Wobbler syndrome, or cervical vertebral malformation (CVM), is a devastating disease that can affect a horse’s neurologic and musculoskeletal systems. It is a structural narrowing of the spinal canal due to a variety of vertebral malformations and leads to spinal cord compression. As a result, horses exhibit clinical signs of spasticity, ataxia, and lack of coordination.
Cervical vertebral instability and cervical static stenosis are the two distinct types of CVM. Cervical vertebral instability causes dynamic spinal cord compression—occurring when the neck is flexed. Horses with dynamic lesions are typically 4 to 18 months of age, and the location of the compression is typically C3-5 (between the cervical vertebrae 3 and 5).
Cervical static stenosis typically affects horses between 1 and 4 years of age and is characterized by narrowing of the cervical canal C5-7 (between the cervical vertebrae 5 and 7). The compression that results is static—occurring regardless of neck position.
Typically, wobbler syndrome is thought of as a developmental disease of young horses and is even included in the classification of developmental orthopedic diseases by some authors. Researchers have looked at this disease in horses over the age of 4 and concluded that it should be kept as a differential diagnosis in older horses as well.
The exact cause of wobbler syndrome in horses is unknown. It is believed that the syndrome is caused by genetic predisposition, feeding excessive amounts of energy and other nutrients, rapid growth, physical trauma, decreased copper/ increased zinc levels, or a combination of these factors