Racing Outlook for Horses Treated for Cervical Vertebral Malformation

Some horses with cervical vertebral malformation (CVM; wobblers) can be treated successfully with dietary and exercise restriction to slow growth and prevent further injury to the spinal cord. Horses that are less than one year of age with mild neurologic deficits are more likely to recover with dietary management. Original studies reported that 83% of conservatively managed young horses went on to start at least one race.

Hoffman and Clark examined race performance in 103 Thoroughbreds with a presumptive diagnosis of CVM. The median (50% above and 50% below) age of study horses was one year. Most affected horses were colts, followed by geldings and fillies. Horses were diagnosed with CVM using standing radiographs of the neck. Only five horses were diagnosed with CVM by myelography (radiographs taken after injection of contrast into the cerebrospinal fluid).

Horses euthanatized upon diagnosis, those with incomplete radiograph reports, or those with a diagnosis of equine protozoal myeloencephalitis were excluded from further analysis. Thirty percent (21/70) of horses treated medically went on to start at least one race. Medical treatments administered to horses in the study included vitamin E supplements, nonsteroidal anti-inflammatory drugs, and corticosteroids.

Horses were typically rested for 3 to 6 months and re-evaluated before going back into training. Horses that started a race had less neurologic deficits than horses that did not start. Horses that did not start a race were more likely to have curvature of neck vertebrae or narrowing of spinal canal when radiographs were evaluated.

In contrast to previous studies, horses with CVM managed conservatively in this study were older and were already in race training, which may explain the relatively low percentage of horses that were eventually able to start a race. If signs of CVM are observed while horses are young (less than 1 year old) and signs of neurologic disease are mild, then the chances of a successful outcome may be better because there is more time to attempt conservative treatment.

Hoffman, C.J., and C.K. Clark. 2013. Prognosis for racing with conservative management of cervical vertebral malformation in Thoroughbreds: 103 cases (2002-2010).  Journal Veterinary Internal Medicine 27:317-323.