Disorder - Transitional Vertebral Segments

Organ Systems Involved
Musculoskeletal

Brief Description

Absence or alteration of specific vertebral segments.

Presenting Signs

In a normal dog, the spinal column can be divided into five major divisions, each categorised by a specific number of vertebrae with a characteristic shape. From the skull, there are seven cervical vertebrae, thirteen thoracic vertebrae, which connect to the ribs, seven lumbar vertebrae, three sacral vertebrae and twenty caudal vertebrae, which make up the tail. Transitional vertebrae are single vertebrae or segments of vertebrae found at a junction between two of the major divisions, which assume characteristics of either of the types. The altered vertebrae may have the 'spines' or the shape of the vertebrae, different to those of the section the segment is contained within. For example, a lumbar vertebra may resemble or even replace a rib. The segments may also become fused. Transitional vertebral segments can only be diagnosed with X-rays; they commonly occur but clinical signs are rarely evident. Severely altered transitional vertebrae at the lumbosacral junction of the spinal column may give rise to secondary changes such as arthritis and spinal nerve damage.

Dogs at Risk

Found more commonly in female dogs

Related Disorders

Spinal Chord Anomalies
Cervical Spondulopathy ('Wobbler' syndrome)
Hemivertebrae
Block Vertebrae
Butterfly Vertebrae

PubMed References
Transitional Vertebral Segments

Further Reference Material [OMIA Number]
1014


Contributor
Anna Tarver