Rhodesian Ridgeback lumbosacral transitional vertebra (LÜW)

WE QUOTE" the IHV

Evaluation in HD findings

More and more often we find on the data evaluated by our experts HD report forms the abbreviation (LÜW), sometimes combined with numerical combinations. We would therefore like to take this opportunity to provide a brief explanation.

The dog’s spine is made up of approximately 50 vertebrae It is divided into five sections, and in each section the number of vertebrae is largely constant.

Most dogs have 7 cervical vertebrae, 13 thoracic vertebrae, 7 lumbar vertebrae, 3 sacral vertebrae and about 20 caudal vertebrae.ANATOMY

The vertebrae of one segment differ from neighboring segments due to their anatomical characteristics. For example, the thoracic vertebrae have a jointed connection to the ribs. The sacral vertebrae, in turn, are fused together to form the sacrum and are in contact with the pelvis. Vertebrae that lie at the transition between two segments and exhibit anatomical characteristics of both segments are called transitional vertebrae. For example, a thoracic vertebra may be missing one or both ribs, or conversely, the last cervical vertebra or the first lumbar vertebra may have ribs on one or both sides.

Such malformations are usually clinically insignificant because they neither cause pain nor disable the dog.

More problematic are the transitional vertebrae at the lumbar-sacral junction, where disc damage is frequently observed even in dogs with normal anatomy. It has been proven that in dogs with a transitional vertebra between the lumbar and sacral bones, the last intervertebral disc is frequently damaged, which can lead to compression and inflammation of the nerves in the spinal canal.

Transitional vertebrae can also cause a tilting of the pelvis, which can lead to one-sided or one-sided heavier

can result in hip dysplasia (HD).

The Dysplasia Commissions in Bern and Zurich have paid increased attention to transitional vertebrae in recent years, noting any pronounced malformation on their medical reports. In collaboration with leading dysplasia experts from Germany, a simple classification of the lumbosacral transitional vertebrae has been developed. It is based on two criteria: a) fusion of the spinous processes of the sacrum and b) symmetry of the connection between the transitional vertebra and the pelvis.

Type 0a normal lumbosacral junction

Type 1Failure of the spinous processes of the first and second sacral vertebrae to fuse

Type 2symmetrical malformation of the transverse processes

Type 3differently shaped transverse processes, i.e. an asymmetric lumbosacral transitional vertebra

It is still not clear whether and how transitional vertebrae are inherited.

Until a final veterinary clarification is obtained, a selection that would only exclude types 2 and 3 from breeding makes no sense from a genetic point of view.

When a dog is approved for breeding by the IHV Internationaler Hunde Verband eV, this finding is not taken into account, as it is still unknown how the different LÜW types are inherited..

In studies conducted by the Zurich Dysplasia Commission, it was encouraging that only 3.5% of dogs had a lumbosacral transitional vertebra. However, the incidence rate varied considerably between breeds. The German Shepherd Dog was disproportionately affected at 5.7%, the Greater Swiss Mountain Dog at 9.4%, and the Shar Pei at 19.2%. Breeding regulations appear to be sensible and could be effective if the heritability is 20-30% or higher. However, it has not yet been clarified how the different forms of LÜW behave genetically, i.e. whether dogs with type 1 can also have offspring with LÜW type 2 or 3, and vice versa. Breeding regulations are therefore not very effective at the moment. Regardless of this, we recommend, purely as a precautionary measure, not using these dogs for breeding. ”

For further information, please refer to our sources.

PDFs that describe the topic very well and also include assistance with X-rays:

PDF - Swiss Archives of Veterinary Medicine/Lumbosacral transitional vertebrae: What significance do they have for the

Health of affected dogs?TO THE HOMEPAGE/TO THE ARCHIVE

PDF - Lumbosacral transitional vertebrae in dogs by Christine Brugger

PDF - Transitional vertebrae in breeding/GKF TO THE HOMEPAGE

Transitional vertebrae at the lumbar-sacral junctionTO THE HOMEPAGE