Published: 17 February 2017

Reducing chronic disorders in toy dog breeds

Canine Chiari-like malformation (CM) is a complex abnormality of the skull, neck and head associated with miniaturisation, which can lead to pain disorders and the spinal cord disease syringomyelia (SM). The number of diagnosed cases and their severity has increased dramatically during the last 20 years and can be seen in many toy breed dogs and their crosses.

Dr Clare Rusbridge, a Reader in Veterinary Neurology at Surrey’s School of Veterinary Medicine, has recently collaborated with neurologists at Fitzpatrick Referrals and Helsinki University and a geneticist at the University of Montreal, to develop a novel MRI mapping technique, which examines a dog’s skull, brain and vertebrae in greater detail. It highlights, via a movie clip, how such disorders develop in toy dog breeds. Clare explains:

The innovative mapping technique used in this study has the potential to provide a diagnostic tool for vets, helping them to quickly identify dogs suffering from these painful disorders.

By examining the footage from the MRI scans, researchers were able to observe the compression of a dog’s brain caused by the premature fusion of bones in the skull. Such fusions also occur at the front of the head causing a dog’s face to become flatter, creating the desirable doll like features common in this breed. A second study revealed how the disease affected different parts of the skull and vertebrae in the Cavalier King Charles Spaniel, Chihuahua and Affenpinscher dog breeds.

Due to poor breeding practices and the popularity of toy dog breeds, many more dogs are suffering from Chiari malformation and Syringomyelia disorder. As the University’s research develops, the team hope to develop computer software to analyse the complex malformation and in doing so develop more sophisticated ways of screening.

Dr Rusbridge’s work has greatly enhanced the understanding of the disease and its risk traits over the years and through shaping veterinary and breeding practice, will ultimately lead to the improved health and welfare of toy dogs.

For more information, visit Dr Clare Rusbridge’s academic profile or the research articles in Plos One

This study was part of Surrey postgraduate Penny Knowler’s PhD work funded by the charity Cavalier Matters.

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