Hemivertebrae (HV) are congenital malformations of the vertebrae causing spinal deformity and are seen commonly in the so called “screw tailed breeds” – English Bulldog, French Bulldog and Boston Terriers as well as the Pug.

Hemivertebrae are also called ‘butterfly’ vertebrae due to the characteristic shape of the vertebral body on radiographs. The incidence is up to 85% in some breeds – the French Bulldog being the most affected: Schlensker and Distl (The Veterinary Journal 2016) found that hemivertebrae have a high degree of hereditability.

Not all dogs with HV develop neurological signs associated with the condition, however when neurological signs do occur they can be devastating. The abnormal vertebrae can cause spinal cord compression which can cause progressive neurological deficits affecting the pelvic legs, progressing from ataxia to paralysis. Urinary and faecal incontinence is common. Spinal decompression and fusion is often required and many dogs do not fully recover.

In this lecture Philip Moses looks at the heritability, incidence, diagnosis and the failed efforts to rid these breeds of this terrible congenital and hereditary disorder.