Some dogs got a shorter end of the stick. It seems like certain small dog breeds might be at risk of aching neurological diseases because of the shape of their skulls, says researcher.
In search of eliminating even more canine diseases in the future, a new study  has found evidence that the skull shape of toy dog breeds, more specifically the Cavalier King Charles Spaniel and the Chihuahua, could be a huge risk facet for some very painful neurological conditions, such as syringomyelia (SM).
Syringomyelia allows for fluid-filled cavities that are known as syrinxes to form in the dog’s spinal cord. The condition is usually secondary to a certain deformity of the skull called Chiari-like Malformation (CM).
Currently, the only treatment for syringomyelia is a very costly surgery, and there is no guarantee that the dog will not relapse once the surgery is performed. This surgery is successful in improving neurological problems and reducing pain in about 80% of cases. In approximately 45% of those cases, this may still have a good quality of life 2 years after surgery. But 50% of these cases will relapse, however, and that is a large risk for dog owners to take.
More study details
The research was performed at the University of Bristol’s School of Veterinary Sciences, in the United Kingdom, by an undergraduate student named Thomas Mitchell. Results of the study, which was published in the journal Canine Genetics and Epidemiology just last month, state that the most significant factor is the shape of a dog’s skull. But there is still much debate between researchers about the primary cause of canine Chiari malformations.
During the study, head shapes of over 130 CKC Spaniels from different countries were measured, and researchers compared those measurements to the frequency of syringomyelia. Although these dogs were from different countries, in addition, a standardized “bony landmark” measuring system was used along with photo analysis by highly trained researchers.
The scientist has found that those canines who had shorter snouts, in comparison to the broadness of their skulls (which is known as brachycephaly), and had a head with a forward-facing dome, were much more likely to develop the neurological disorder.
Mitchell is hoping that his findings will allow breeders to selectively breed their dogs away from the condition for the next few generations, and it could possibly even change breeding laws in the future as well. By choosing appropriate mating pairs and offspring that will continue their breeding program, syringomyelia could essentially be wiped out almost entirely within just 3 or 4 generations.
“The identification of an appearance that might protect against developing the disease is a significant step forward in tackling this painful condition,” says Mitchell.
“The study also provides guidance to breed clubs, breeders, and judges that have responsibility to avoid obvious conditions or exaggerations which would be harmful in any way to the health, welfare, or soundness of the animal.”
This study should undoubtedly serve as a wake-up call to all breeders who select their dogs mainly to achieve a certain look. It may set breeders back a step in creating the perfect dog, but it will certainly help protect the spread of these kinds of diseases and demonstrate an example how we can ensure a healthier future canine generation. More research will be done later to try and link physical traits to different diseases and confirm current findings.
- Thomas J Mitchell et al. Syringomyelia: determining risk and protective factors in the conformation of the Cavalier King Charles Spaniel dog. Canine Genetics and Epidemiology 2014, 1:9. doi: 10.1186/2052-6687-1-9