Chiari Malformation/Syringomyelia Scheme (CM/SM scheme)

The aim of this Scheme is to reduce and eliminate the incidence of chiari malformation and syringomyelia (CM/SM) in dogs. MRI scans are graded by 2 expert Scrutineers appointed by a BVA panel. The results should then be used to make informed breeding decisions.

The Scheme is open to all dogs and breeds including crossbreeds and non-Kennel Club registered dogs.

Chiari malformation/syringomyelia in dogs

Chiari-like malformation (CM) is characterised by a mismatch in size between the brain (which is too large) and the skull (which is too small). This may block the opening from the skull to the spine and alter the flow of cerebrospinal fluid (CSF) around the spinal cord. As a result, fluid-filled cavities called syrinxes can develop within the spinal cord, with the condition being called syringomyelia (SM). The conditions are most often seen in Cavalier King Charles Spaniels.

The conditions can cause intense pain and may have serious effects on the health, welfare and behaviour of dogs.

Signs of chiari malformation/syringomyelia

Although some dogs can seem fine, other dogs may experience intense pain and suffering. Signs include:

  • Unable or unwilling to exercise
  • Head scratching - 'air-scratch' without making contact with the body
  • Increased sensitivity to touch, especially around the head, neck, shoulders and breast bone
  • Rubbing the face repeatedly
  • Excessively licking their paws

It is very important to discuss any concerns with your veterinary surgeon.

Treatment

There is no one specific treatment for chiari malformation/syringomyelia. Pain relief can be prescribed and surgery is an option, however it can be expensive and not always successful. You should always seek advice from your veterinary surgeon.

Common breeds at risk

Chiari malformation/syringomyelia has been shown to be inherited in the Cavalier King Charles Spaniel and the Griffon Bruxellois and is suspected to be inherited in the King Charles Spaniel.

Other breeds reported with the condition include:

Maltese
Yorkshire Terriers
Chihuahuas Papillons
Pomeranians Affenpinschers
Havanese Boston Terriers
Staffordshire Bull Terriers

Download the full breed breakdown (329 KB PDF).

The Scheme is open to all dogs, including crossbreeds. Visit the Kennel Club Breed Information Centre for further information on whether the scheme is relevant to your breed.

    • For vets
    • For dog breeders
    • For dog owners

    For vets

    The Chiari Malformation/Syringomyelia Scheme

    The aim of this Scheme is to reduce and eliminate the incidence of chiari malformation and syringomyelia (CM/SM) in dogs. MRI scans are graded by 2 expert Scrutineers appointed by a BVA panel. The results should then be used to make informed breeding decisions.

    Syringomyelia has been recognised as a serious problem in the Cavalier King Charles Spaniel (CKCS), Griffon Bruxellois and occasionally in other toy breeds. It has been shown to be a genetically-transmitted condition (Lewis et al., 2012) and in many dogs, progresses through the first few years of life (Parker et al., 2011).

    Download our leaflet on chiari malformation/syringomyelia (2.26 MB PDF) in dogs for more information on the conditions and the Scheme.

    The CM/SM Scheme examines DICOM digital MRI images of the brain and cranial (upper) cervical spinal cord of dogs for changes indicative of CM and SM and issues certificates in respect of that examination. If SM is present, the certificate will also detail the maximum diameter of the syrinx in the cranial part of the neck. These results are intended to assist dog breeders in their selection of breeding stock.

    Information for submitting vets

    Please read the CM/SM Scheme Procedure Notes (52 KB PDF) for helpful instructions on using the Scheme.

    The minimum age of a dog for submission to the CM/SM scheme is 1 year, there is no upper age limit. As syringomyelia is a progressive disease, scanning is best performed at 5 years of age and older.

    Cost of submission

    See cost of submissions and examinations for a full breakdown.

    Results

    Once the MRI scan has been graded by BVA appointed scrutineers, a CHS certificate (296 KB PDF) will be issued and sent to the submitting vet.

    The certificate will show a grade for chiari-like malformation and a separate grade for syringomyelia. The lower the grade the better. The best grade is 0 and the worst is 2. The age of the dog at the time of scanning is also shown in the grading.

    The grade is qualified with a letter indicating the age group at the time of scanning as follows: a = more than 5 years, b = 3 to 5 years or age, c = 1 to 3 years of age.

    There are currently no Estimated Breeding Values available for the CM/SM, however there are breeding recommendations (14 KB PDF).

    Publication of results

    The results of Kennel Club registered dogs will be published on the Kennel Club Mate Select website if a specific condition is known to be inherited and certified as such.

    For dog breeders

    The Chiari Malformation/Syringomyelia Scheme

    The aim of the Chiari Malformation/Syringomyelia Scheme is to reduce and eliminate the incidence of chiari malformation and syringomyelia in dogs. The Scheme uses MRI scans to examine the brain and upper neck. The scans are then graded by expert veterinary surgeons, otherwise known as Scrutineers, appointed by BVA. The results can then be used to make informed breeding decisions.

    The minimum age of a dog for submission to the Chiari Malformation/Syringomyelia Scheme is 1 year, there is no upper age limit. As syringomyelia is progressive disease scanning is best performed at 5 years of age and older, which is late for breeding. Therefore, it is recommended that breeders consider scanning their dogs more than once, for example before breeding and again at 5 years of age or later.

    How to make a submission

    1. Contact your veterinary surgeon and request that your dog be scanned for assessment under the Chiari Malformation/Syringomyelia Scheme.
    2. When taking your dog for the MRI scan you must have relevant registration documentation with you.
    3. The veterinary surgeon who carried out the MRI scan will then submit the images and relevant information to BVA.
    4. Scrutineers appointed by BVA will grade the images.
    5. The results will be returned to the veterinary surgeon and passed on to yourself.
    6. If your dog is registered with the Kennel Club, the results will also be published on the Kennel Club website.

    Cost of submissions

    See cost of submissions and offers for a full breakdown.

    CM/SM Scheme fund

    BVA and The Kennel Club Charitable Trust have pledged up to £30,000 to support dog owners concerned about CM/SM. This funding will allow owners who had MRI scans taken before the start of the scheme in 2012 to have their scans accessed by the scheme, and the results published for free - a process to the value of £100.

    To participate in this offer, MRI scans must have been taken before January 2012 and they must be from Kennel Club registered dogs. Not all MRI scans may be suitable for assessment. To find out more about the offer, email chs@bva.co.uk.

    The results

    The certificate (292 KB PDF) will show a grade for chiari-like malformation and a separate grade for syringomyelia. The lower the grade the better. The best grade is 0 and the worst is grade 2. The age of the dog at the time of scanning is also show in the grading:

    The grade is qualified with a letter indicating the age group at the time of scanning as follows: a = more than 5 years, b = 3 to 5 years or age, c = 1 to 3 years of age.

    There are currently no Estimated Breeding Values available for the chiari malformation/syringomyelia, however there are breeding recommendations (16 KB PDF).


    Chiari-like malformation (CM)Syringomyelia
    Grade 0 - No Chiari malformation Grade 0 - Normal (no central canal dilation, no pre-syrinx, no syrinx)
    Grade 1 - Cerebellum indented (not rounded) Grade 1 - Central canal dialtion (CCD) less than 2mm in diameter
    Grade 2 - Cerebellum impacted into, or herniated through the opening at the rear of the skull (the foramen magnum) Grade 2 - Syringomyelia or separate syrinx, pre-syrinx with or without central canal dialtion

    Appeals

    An owner has a right to appeal with regards to the results of a CM/SM assessment. The procedure can be found on our appeals page.

    Further information

    For dog owners

    The Chiari Malformation/Syringomyelia Scheme

    The Scheme uses MRI scans to examine the brain and upper neck. The scans are then graded by expert veterinary surgeons appointed by a BVA panel. The results from the examination can then be used to make breeding decisions.

    What does the chiari malformation/syringomyelia grade mean?

    If you are going to purchase a puppy that could be at risk of chiari malformation/syringomyelia (CM/SM), it is very important that you see the parents’ results for the CM/SM screening before you commit to buying a puppy. You can use The Puppy Contract to aid you in asking all the right questions.

    The certificate will show a grade for chiari-like malformation and a separate grade for syringomyelia. The lower the grade the better - the best grade is 0 and the worst is 2. Download our breeding recommendations (16 KB PDF).

    How to screen your dog for chiari malformation/syringomyelia

    For information on how to get your dog screened for chiari malformation/syringomyelia via the Canine Health Schemes, please see the process below:

    1. Contact your veterinary surgeon and request that your dog be scanned for assessment under the CM/SM Scheme.
    2. The veterinary surgeon who carried out the MRI scan will then submit the images and relevant information to BVA.
    3. Expert veterinary surgeons appointed by BVA will grade the images.
    4. The results will be returned to the veterinary surgeon and passed on to yourself.
    5. If your dog is registered with the Kennel Club, the results will also be published on the Kennel Club website.

    See cost of submissions and offers for a full breakdown.

    Further information