I enjoyed meeting neurologist Prof. Jacques Penderis today at the annual Irish veterinary conference in Dublin. Prof Penderis is based at the University of Glasgow and is the leading researcher into episodic falling syndrome (EFS), a neurological condition known only in Cavaliers. He very generously gave me about an hour of his time in advance of giving three different presentations spanning the afternoon of the first day of the conference. I also had permission to return and attend his final presentation on neurological conditions in Cavaliers, which was really interesting.
I am going to write all of this up in more detail, probably tomorrow, but I wanted to flag one of the very exciting highlights, which is the fact that his team will be producing a genetic test for episodic falling to be released within the coming months, probably around April. This was developed in partnership with the animal health trust (AHT) in the UK. This is a very exciting development! His research team announced it had pinpointed the gene responsible for EFS last November. It turns out the condition is caused by a simple recessive trait, which makes it much easier to exactly locate and also easier to address, as well as easier to create a genetic test. Basically, breeders will be able to test to see whether any dog carries the gene for EFS. By eliminating dogs with the gene–or at least initially breeding dogs with the gene to dogs without the gene iF a wider gene pool is needed, as is probably the case as he describes this as a 'widespread' condition, both internationally and within the breed generally–gradually the incidence will drop in the condition could be entirely eradicated.
He said the gene involves the brain, and this is definitely not a muscular disorder (he said one paper was published that erroneously stated this a while back, but it is clear this is not the case). he said the gene is a quite interesting one, and that it has not in the past been known to be involved with genetic conditions, and the discovery may be of help in human medicine. But he could not give me any detail because the results are not yet published.
He also noted that he would define episodic falling as a *common*, not a rare condition in the breed. He said the incidence of EFS would be much higher than of epilepsy, for example–he would consider cavaliers to be “moderately” affected by epilepsy. He also said the vast majority of cases are very mild, with many stabilizing by age 1. He said it is actually quite rare for cases to be severe or to require a dog to be euthanized.
We split the hour pretty much evenly between EFS and SM. Some of the key points that I found interesting during our discussion on SM was his observation that they see almost no other breed than cavaliers coming in with SM, and he thinks it is actually quite rare in other breeds, including the toy breeds/brachycephalic dogs. He says they do not even see it as an occasional incidental finding when doing MRIs on other breeds, whereas they would commonly find CM and often SM on any cavalier MRI. He said he is not sure why one center in the US has seen up to 40% of its SM caseload in other breeds, and wonders if this is due to a local problem in certain US populations of breeds. he noted yorkies are one breed they see with SM as well.
He also would be quite conservative on choosing whether to do surgery– he feels surgery is something to consider after medication fails, or in young severely affected dogs. He said he did not feel there was any outstanding evidence so far that surgery is a better choice than medications and notes existing studies are more about anecdotal evidence on whatever approach a given team is doing. (This is true–there has been no proper comparative study.) He also noted, however, that perhaps there were benefits to doing surgery when affected dogs were young, before their syrinxes have a chance to expand and cause damage.
He is quite convinced that the problem of SM and many of these other neurological issues lies in the shape of the cavalier skull; he said some "extreme" internal feature not yet identified that has been bred in which now sometimes causes serious problems inside the brain and the spine as a result, amd a high degree of CM/SM ( though he uses the terms Chiari malformation and syringohydromyelia himself). He emphasized (as have other researchers) that this has nothing to do with any obvious outward shape of an individual skull or head but has to do with the fact that the dog is generally in the brachycephalic category and that there is some *internal* element affected by this particular type of skull in this particular breed. he noted that there are neurological conditions known throughout the brachycephalic breeds.
He encouraged breeders to continue to scan and submit scans and DNA As the only way forward for addressing SM, which he described as a more serious and difficult problem than EFS. He said that it may be in future that the Cavalier will be pointed to as one of the healthier breeds because with breeder support, some of its genetic problems will have been identified and breeders will have the tools to breed away from these neurological issues.
He also noted that he felt it was beneficial that different researchers approach these health issues from different directions and with different ideas, including treatment ideas, because this is more beneficial in trying to understand and resolve the problem. in that sense, he indicated it would be quite counterproductive for every researcher to have a common agreement around these health issues. The fact that many people have had many ideas has helped already to eliminate some ideas and hone in on others.
Anyway those are some highlights. I attended his one hour presentation and took quite a few notes. He went through a number of neurological conditions that he said feature more predominantly in the breed than in many other breeds. when I get a chance to write up the presentation I will note all of those.
I am going to write all of this up in more detail, probably tomorrow, but I wanted to flag one of the very exciting highlights, which is the fact that his team will be producing a genetic test for episodic falling to be released within the coming months, probably around April. This was developed in partnership with the animal health trust (AHT) in the UK. This is a very exciting development! His research team announced it had pinpointed the gene responsible for EFS last November. It turns out the condition is caused by a simple recessive trait, which makes it much easier to exactly locate and also easier to address, as well as easier to create a genetic test. Basically, breeders will be able to test to see whether any dog carries the gene for EFS. By eliminating dogs with the gene–or at least initially breeding dogs with the gene to dogs without the gene iF a wider gene pool is needed, as is probably the case as he describes this as a 'widespread' condition, both internationally and within the breed generally–gradually the incidence will drop in the condition could be entirely eradicated.
He said the gene involves the brain, and this is definitely not a muscular disorder (he said one paper was published that erroneously stated this a while back, but it is clear this is not the case). he said the gene is a quite interesting one, and that it has not in the past been known to be involved with genetic conditions, and the discovery may be of help in human medicine. But he could not give me any detail because the results are not yet published.
He also noted that he would define episodic falling as a *common*, not a rare condition in the breed. He said the incidence of EFS would be much higher than of epilepsy, for example–he would consider cavaliers to be “moderately” affected by epilepsy. He also said the vast majority of cases are very mild, with many stabilizing by age 1. He said it is actually quite rare for cases to be severe or to require a dog to be euthanized.
We split the hour pretty much evenly between EFS and SM. Some of the key points that I found interesting during our discussion on SM was his observation that they see almost no other breed than cavaliers coming in with SM, and he thinks it is actually quite rare in other breeds, including the toy breeds/brachycephalic dogs. He says they do not even see it as an occasional incidental finding when doing MRIs on other breeds, whereas they would commonly find CM and often SM on any cavalier MRI. He said he is not sure why one center in the US has seen up to 40% of its SM caseload in other breeds, and wonders if this is due to a local problem in certain US populations of breeds. he noted yorkies are one breed they see with SM as well.
He also would be quite conservative on choosing whether to do surgery– he feels surgery is something to consider after medication fails, or in young severely affected dogs. He said he did not feel there was any outstanding evidence so far that surgery is a better choice than medications and notes existing studies are more about anecdotal evidence on whatever approach a given team is doing. (This is true–there has been no proper comparative study.) He also noted, however, that perhaps there were benefits to doing surgery when affected dogs were young, before their syrinxes have a chance to expand and cause damage.
He is quite convinced that the problem of SM and many of these other neurological issues lies in the shape of the cavalier skull; he said some "extreme" internal feature not yet identified that has been bred in which now sometimes causes serious problems inside the brain and the spine as a result, amd a high degree of CM/SM ( though he uses the terms Chiari malformation and syringohydromyelia himself). He emphasized (as have other researchers) that this has nothing to do with any obvious outward shape of an individual skull or head but has to do with the fact that the dog is generally in the brachycephalic category and that there is some *internal* element affected by this particular type of skull in this particular breed. he noted that there are neurological conditions known throughout the brachycephalic breeds.
He encouraged breeders to continue to scan and submit scans and DNA As the only way forward for addressing SM, which he described as a more serious and difficult problem than EFS. He said that it may be in future that the Cavalier will be pointed to as one of the healthier breeds because with breeder support, some of its genetic problems will have been identified and breeders will have the tools to breed away from these neurological issues.
He also noted that he felt it was beneficial that different researchers approach these health issues from different directions and with different ideas, including treatment ideas, because this is more beneficial in trying to understand and resolve the problem. in that sense, he indicated it would be quite counterproductive for every researcher to have a common agreement around these health issues. The fact that many people have had many ideas has helped already to eliminate some ideas and hone in on others.
Anyway those are some highlights. I attended his one hour presentation and took quite a few notes. He went through a number of neurological conditions that he said feature more predominantly in the breed than in many other breeds. when I get a chance to write up the presentation I will note all of those.
