Tag Archives: Cavalier King Charles Spaniels

Skull shape and its implication for animal welfare

Syringomyelia (SM) is a painful condition in dogs that is more common in toy breeds like the Chihuahua and the Cavalier King Charles Spaniel. It involves the formation of fluid-filled cavities, known as syrinxes, in the spinal cord.  In these toy breeds, SM is usually secondary to a specific malformation of the skull called Chiari-like Malformation, CM for short.

Cavalier King Charles Spaniel

New research conducted at the University of Bristol’s School of Veterinary Sciences has identified two significant risk factors associated with these painful neurological conditions.

Identifying a head shape in dogs that is associated with these diseases would allow for selection away from these conditions and could be used to further breeding guidelines. Dogs were measured in several countries using a standardised “bony landmark” measuring system and photo analysis by trained researchers.

The researchers found two significant risk factors associated with CM/SM in the skull shape of the Cavalier King Charles Spaniel.  These were the extent of the broadness of the top of skull relative to its length, also known as brachycephaly, and the distribution of doming of the skull. The study suggests that brachycephaly, with resulting doming towards the front of the head, is associated with both conditions.

Thomas Mitchell, who was the undergraduate involved in the study, says “The study also provides guidance to breed clubs, breeders and judges that have a responsibility to avoid obvious conditions or exaggerations which would be harmful in any way to the health, welfare or soundness of the breed.  It will also provide vets with verified advice to provide to breeders outside the show ring and to occasional hobbyists.”

This research has been published online in the journal Canine Genetics and Epidemiology.

Source:  University of Bristol media release

Please also see my earlier post on Your dog may have a permanent headache, which discusses the Chiari malformation and earlier research on the Griffon Bruxellois.

Kathleen Crisley, specialist in dog massage, rehabilitation and nutrition/food therapy, Canine Catering Ltd, Christchurch, New Zealand

Your dog may have a permanent headache

Through selective breeding, toy breeds including the Griffon Bruxellois, Cavalier King Charles Spaniels, Chihuahuas and their crosses may have to live with a permanent headache and other maladies.

A Griffon Bruxellois Photo by © Vincent / Fotolia

A Griffon Bruxellois
Photo by © Vincent / Fotolia

Research published in the journal PloS One by researchers at the University of Surrey has identified the specific effect Chiari malformation has on the shape of a dog’s skull and brain.

Researchers took brain, skull and vertebrae measurements of 155 Griffon Bruxellois and compared dogs affected by the condition, with normal Griffons. They discovered that Griffons with the disease had taller foreheads and that it had also caused the shape of the brain to change, with severely affected animals having their cerebellum pushed underneath the main part of the brain.

The taller forehead makes some toy breeds look like a doll, making them more attractive to people looking to purchase a dog.

Although it can be asymptomatic, in many dogs Chiari malformation can cause headaches, problems with walking or even paralysis.

Lead author, Dr Clare Rusbridge says: “Chiari malformation can be described as trying to fit a big foot into a small shoe. It can be very painful, causing headaches and pressure on the brain and can result in fluid filled cavities in the spinal cord. Our latest discoveries will be significant in driving this research forward and hopefully allow us to identify which genes may be associated with the condition. Our next steps will be to apply our technique to other breeds with Chiari malformation and investigate more sophisticated ways of screening, so that risk of disease can be detected more easily, at an earlier age and with a single MRI scan.”

The research team wants to work with responsible breeders to use scanning technology so they can remove the condition from the breeding population.

Source:  AlphaGalileo press release