Tag Archives: Chiari malformation

AI could help diagnose dogs suffering from chronic pain

A new artificial intelligence (AI) technique developed by the University of Surrey could eventually help veterinarians quickly identify Cavalier King Charles Spaniel (CKCS) dogs with a chronic disease that causes crippling pain. The same technique identified unique biomarkers which inspired further research into the facial changes in dogs affected by Chiari-like malformation (CM).

CKCS

Photo by Getty Images

Cavalier King Charles Spaniels are predisposed to CM – a disease which causes deformity of the skull, the neck (cranial cervical vertebrae) and, in some extreme cases, lead to spinal cord damage called syringomyelia (SM). While SM is straightforward to diagnose, pain associated with CM is challenging to confirm and why this research is innovative.

In a paper published by the Journal of Veterinary Internal Medicine, researchers from Surrey’s Centre for Vision, Speech and Signal Processing (CVSSP) and School of Veterinary Medicine (SVM) detail how they used a completely automated, image mapping method to discover patterns in MRI data that could help vets identify dogs that suffer from CM associated pain. The research helped identify features that characterise the differences in the MRI images of dogs with clinical signs of pain associated with CM and those with syringomyelia from healthy dogs. The AI identified the floor of the third ventricle and its close neural tissue, and the region in the sphenoid bone as biomarkers for pain associated with CM and the presphenoid bone and the region between the soft palate and the tongue for SM.

Dr Michaela Spiteri, lead author of the study from CVSSP, said: “The success of our technique suggests machine learning can be developed as a diagnostic tool to help treat Cavalier King Charles Spaniel’s that are suffering from this enigmatic and terrible disease. We believe that AI can be a useful tool for veterinarians caring for our four-legged family members.”

Identification of these biomarkers inspired a further study, also published in the Journal of Veterinary Internal Medicine, which found that dogs with pain associated with CM had more brachycephalic features (having a relatively broad, short skull) with reduction of nasal tissue and a well-defined stop.

SVM student, Eleonore Dumas, whose 3rd year project formed part of the study data, said: “Being able to contribute to the development of diagnostic tools that allow for earlier diagnosis of patients suffering from this painful condition has been both challenging and incredibly rewarding.”

Dr Penny Knowler, lead author of the study from SVM, said: “This study suggests that the whole skull, rather than just the hindbrain, should be analysed in diagnostic tests. It also impacts on how we should interpret MRI from affected dogs and the choices we make when we breed predisposed dogs and develop breeding recommendations.”

Adrian Hilton, Distinguished Professor from the University of Surrey and Director of CVSSP, said: “This project demonstrates the potential for AI using machine learning to provide new diagnostic tools for animal health. Collaboration between experts in CVSSP and Surrey’s School of Veterinary Medicine is pioneering new approaches to improve animal health and welfare.”

Both studies were funded by the Memory of Hannah Hasty Research Fund. Hannah was a CKCS unaffected by CM/ SM and a much beloved companion, giving her owner much support and joy. The AI study was also supported by the Pet Plan Charitable Trust.

The findings of the studies are available to read on the Journal of Veterinary Internal Medicine website here and here.

New hope for diagnosis of Chiari-malformation in toy dog breeds

Continuing to build on their specialist work in this area, researchers in collaboration with neurologists at Fitzpatrick Referrals and Helsinki University and a geneticist at the University of Montreal, have developed two separate studies, published the journal PLOS ONE last month, to learn more about these painful conditions affecting toy dogs.

Study one focused on how the Chiari malformation and Syringomyelia disorder affects the Cavalier King Charles Spaniel, a breed which is predisposed to the condition.

ckc-spaniels

Chiari malformation is the premature fusion of bones in the skull, which alters the flow of cerebrospinal fluid, resulting in a collection of fluid pockets within the spinal cord. These fluid pockets are commonly known as Syringomyelia and over time can cause irreversible damage to a dog’s spinal cord.

Using a novel MRI mapping technique, which can standardise images for different size dogs, researchers were able to examine a section of the dog’s skull, brain and vertebrae in greater detail and highlight via a movie clip how such disorders develop in the Cavalier King Charles Spaniel.

Examining the footage from the MRI movie clip, 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 often desirable doll like features common in this breed.

Study two examined characteristics that increased the risk of Syringomyelia in the Cavalier King Charles Spaniel, Chihuahua and the Affenpinscher dog breeds. Using a similar technique to study one, the study found that skull and neck conformation that increased the risk for Syringomyelia associated with Chiari-like malformation were subtly different between breeds.

Researchers found that Syringomyelia-affected Chihuahua’s tended to have a smaller angle between the base of the skull and the first and second neck vertebrae, whereas the Affenpinshers had a smaller distance between the first and second vertebrae. Cavalier King Charles Spaniels had reduced space between the joint on the skull base and the first cervical vertebrae. All breeds had a reduced hind skull which altered the angulation of the skull base with neighbouring bones in affected dogs and observed in the movie clips.

Dr Clare Rusbridge, from the University of Surrey, said: “Toy dogs are increasingly popular and as such demand for these breeds is unprecedented. Due to selection for rounded head shapes with short muzzles we are seeing more and more dogs with the painful Chiari malformation and Syringomyelia disorder.”

“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.”

Source:  University of Surrey media release

My other posts on toy breeds and the Chiari malformation include:

Cross-breeding to eradicate Chiari syndrome

In a new study published in the journal PLOS ONE, scientists from the University of Surrey, working with an experienced breeder in the Netherlands, examined how the skull and brain of toy dogs change when a Brussels Griffon with Chiari-like malformation is crossed with an Australian Terrier.  The succeeding hybrid puppy is then back crossed to a Brussels Griffon to give some of the features of the Brussels Griffon, but keeping the longer skull of the Australian Terrier.

Griffon and cross breed

Second-generation backcross and purebred Brussel Griffon Sire Photo credit: Henny van der Berg

The results from the study showed it is possible to breed a dog which had the external features of a short-nosed Brussels Griffon and reduce the risk of Chiari malformation, a debilitating condition found in toy dogs and affecting 1 in 1,280 humans.  The disease is characterised by premature fusion of skull bones forcing parts of the brain to push through the opening in the back of the skull causing fluid filled cavities to develop in the spinal cord. Chiari malformation causes headaches, problems with walking or even paralysis and has become prevalent in some toy breed dogs as a result of selective breeding.

The breeder, Henny van der Berg proposed the project idea after an accidental mating between two of her dogs.  The four-year study analysed five traits on magnetic resonance images (MRI) scans and how they changed generation by generation in the family of 29 dogs.  Using a careful selection of head shape and MRI scans over two generations, the findings revealed it was possible to breed a dog which had the external features of a Brussels Griffon, but is less susceptible to Chiari malformation.

“This is a true collaboration with breeders and researchers working together and using their expertise to improve the health of dogs,” said Dr Clare Rusbridge from the University of Surrey.

“Our study investigated how the characteristics of this disease is inherited in the family.  Such knowledge could help in tackling this debilitating disease in toy dog breeds.  We hope our research will help develop more sophisticated ways of screening and improve breeding guidelines by creating robust breeding values.”

The team at the University of Surrey is now collaborating with geneticists at the University of Montreal, and correlating the skull and brain traits visualised on magnetic resonance images with the dog genome. This information will then be translated to humans.

Source:  University of Surrey media release

My other posts about Chiari malformation include:

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