BVA/KC Chiari-malformation and Syringomyelia Testing Scheme for Dogs

In order to improve the health of pedigree dog breeds and reduce the incidence rates of hereditary and conformation problems within specific pedigree breeds, The Kennel Club (in association with the British Veterinary Association) oversees a number of testing and screening schemes for various health conditions.

All of the conditions covered under the respective screening schemes are considered to be prevalent enough within the affected breeds to pose a risk to the wider health and wellness of the breed as a whole, and tend to be serious or potentially life-threatening problems that can have a significant and negative impact upon affected dog’s quality of life.

Two of the most widely publicised and problematic conditions that are covered under The Kennel Club’s health schemes are chiari malformation and syringomyelia, two separate and serious conditions that often occur simultaneously.

In this article, we will look at chiari malformation and syringomyelia in more detail, including what sort of dog breeds can be affected by these conditions, and how they can be tested for. Read on to learn more.

What is chiari malformation?

Chiari malformation is a malformation of the skull and brain that is classed as a developmental abnormality, in which the brain itself is too large for the dog’s skull. This condition can present in various different ways, but usually the space within the skull is too short, which means that the cerebellum and brainstem are pushed out into the hole at the back of the skull where the spine begins, obstructing the normal flow of cerebrospinal fluid.

This is of course potentially very painful for affected dogs.

What is syringomyelia?

Syringomyelia often accompanies chiari malformation in dogs because it is is a condition that affects the cerebrospinal fluid. The condition occurs when an obstruction is present affecting the normal flow of cerebrospinal fluid from the brain to the spinal cord, which means that the fluid is forced into the spinal cord, where it then dilates into fluid-filled pockets, which can cause nerve damage.

Chiari malformation and syringomyelia often present in dogs simultaneously, because chiari malformation as mentioned compresses the skull and obstructs the flow of cerebrospinal fluid.

What sort of dogs can be affected by these conditions?

Any dog can theoretically be affected by chiari malformation and/or syringomyelia, however, these conditions are much more prevalent within small dog breeds with brachycephalic faces than they are in larger dogs with normal muzzle formation.

The breeds considered by The Kennel Club to be at the greatest risk of these conditions are as follows:

• Cavalier King Charles spaniel
• Affenpinscher
• Chihuahua
• Griffon Bruxellois
• Havanese
• King Charles spaniel
• Maltese
• Papillon
• Pomeranian

Whilst The Kennel Club strongly recommends testing for all of these dog breeds, participation in the testing scheme is currently voluntary.

Should my dog be tested?

If you own a dog from any one of the above breeds and you wish to use them for breeding, it is wise to get your dog tested first to ensure that they are likely to produce a healthy litter. Syringomyelia and chiari malformation can be hugely painful conditions for affected dogs, and there is no way to treat or improve the conditions.

Even dogs that appear to be fine and unaffected may have borderline conformation problems that can become amplified in their offspring, and so even apparently healthy dogs of at-risk breeds should be tested prior to breeding, as should the other dog involved in any mating match.

How is testing performed?

Chiari malformation and syringomyelia cannot be diagnosed or predicted by means of DNA testing, and so in order to find out a dog’s grade for the two conditions, they have to undergo an MRI scan.

Additionally, the MRI scan must be performed at a specialist veterinary centre that is approved to follow the necessary protocols to ensure the proper quality of the scanning images performed. Once the images have been created, the clinic or veterinary service that performed the scan sends the images directly to the British Veterinary Association for assessment by a specialist panel of radiologists and veterinary neurologists.

The grading result is then sent to the vet or clinic that performed the scan in order for them to inform the owner of the dog of their result, and an additional copy is sent to The Kennel Club to be recorded on the breed’s database, and is also published in The Kennel Club’s breed records supplement.

The fee for the MRI scan itself is determined by the clinic that carries out the scan, and as well as this cost, there is an additional fee of £100 including VAT payable for the panel grading of the results themselves.

If for any reason the owner of the dog in question disagrees with the grading given, the results can be appealed, which attracts an additional cost.