DEGENERATIVE MYELOPATHY IN BOXERS
Dozer, loved by Cara Armour
What is DM?
Canine degenerative myelopathy (also known as chronic degenerative radiculomyelopathy) is a progressive disease of the spinal cord in older dogs. The disease has an insidious onset typically between 7 and 14 years of age. It begins with a loss of coordination (ataxia) in the hind limbs. As of July 15, 2008 the mutated gene responsible for DM has been found present in 43 breeds including German Shepherds, Boxers, Chesapeake Bay Retrievers, Rhodesian Ridgebacks, and both breeds of Welsh Corgis. The disease is chronic and progressive, and resulting in paralysis.
The myelin is an insulating sheath around neurons in the spinal cord. One proposed cause of degenerative myelopathy is that the immune system attacks this sheath, breaking it down. This results in a loss of communication between nerves in lower body of the animal and the brain.
Testing:
The Orthopedic Foundation For Animals has a DNA test that can be purchased to see if their dog carries the mutated genes for DM. The test is for any dog but is only recommended for certain breeds. The test consists of a cheek swab (using something similar to a Q-tip to swab the inside of the cheek to submit for testing). All Gentry boxers are tested for the DM genes and their results are published on the OFA website. We conduct our breeding program so that we will not produce puppies with A/A gene composition.
According to the OFA, as of this writing, of the over 2100 Boxers tested for DM, only 17% tested clear (Normal/Normal). Go HERE for the latest statistics.
The test checks for the mutated gene that will tell if your dog may be affected by degenerative myelopathy, if it is a carrier, or if it is unaffected.
The results are:
* Normal / Normal (N/N) – this means your dog does not have the mutated strain and it will not develop degenerative myelopathy. (clear)
* Normal / Abnormal (N/A) – this means your dog is a carrier of the gene but will not develop degenerative myelopathy. (carrier)
* Abnormal / Abnormal (A/A) – this means that your dog carries two alleles for degenerativemyelopathy and may develop degenerative myelopathy (affected). Not all dogs with A/A results will develop DM.
Symptoms:
Degenerative myelopathy initially affects the back legs and causes muscle weakness and loss, and lack of coordination. These cause a staggering affect that may appear to be arthritis. The dog may drag one or both rear paws when it walks. This dragging can cause the nails of one foot to be worn down. The condition may lead to extensive paralysis of the back legs. As the disease progresses, the animal may display symptoms such as incontinence and has considerable difficulties with both balance and walking. If allowed to progress, the animal will show front limb involvement and extensive muscle atrophy. Eventually cranial nerve or respiratory muscle involvement necessitates euthanasia. Progression of the disease is generally slow but highly variable. The animal could be crippled within a few months, or may survive up to three years or more.
Causes:
The etiology of this disease is unknown. Recent research has shown that a mutation in the SOD1 gene is a risk factor for developing degenerative myelopathy in several breeds. Mutations in SOD1 are also associated with familial amyotrophic lateral sclerosis (Lou Gehrig’s disease) in people.
Known causes of spinal cord dysfunction should be excluded before accepting the diagnosis of degenerative myelopathy; disc disease (protrusions) or spinal cord tumours can cause compression of the spinal cord with similar signs to degenerative myelopathy.
Treatment:
Degenerative myelopathy is a non-reversible, progressive disease that cannot be cured. There are no treatments that have been clearly shown to stop or slow progression of DM.
Canine degenerative myelopathy (also known as chronic degenerative radiculomyelopathy) is a progressive disease of the spinal cord in older dogs. The disease has an insidious onset typically between 7 and 14 years of age. It begins with a loss of coordination (ataxia) in the hind limbs. As of July 15, 2008 the mutated gene responsible for DM has been found present in 43 breeds including German Shepherds, Boxers, Chesapeake Bay Retrievers, Rhodesian Ridgebacks, and both breeds of Welsh Corgis. The disease is chronic and progressive, and resulting in paralysis.
The myelin is an insulating sheath around neurons in the spinal cord. One proposed cause of degenerative myelopathy is that the immune system attacks this sheath, breaking it down. This results in a loss of communication between nerves in lower body of the animal and the brain.
Testing:
The Orthopedic Foundation For Animals has a DNA test that can be purchased to see if their dog carries the mutated genes for DM. The test is for any dog but is only recommended for certain breeds. The test consists of a cheek swab (using something similar to a Q-tip to swab the inside of the cheek to submit for testing). All Gentry boxers are tested for the DM genes and their results are published on the OFA website. We conduct our breeding program so that we will not produce puppies with A/A gene composition.
According to the OFA, as of this writing, of the over 2100 Boxers tested for DM, only 17% tested clear (Normal/Normal). Go HERE for the latest statistics.
The test checks for the mutated gene that will tell if your dog may be affected by degenerative myelopathy, if it is a carrier, or if it is unaffected.
The results are:
* Normal / Normal (N/N) – this means your dog does not have the mutated strain and it will not develop degenerative myelopathy. (clear)
* Normal / Abnormal (N/A) – this means your dog is a carrier of the gene but will not develop degenerative myelopathy. (carrier)
* Abnormal / Abnormal (A/A) – this means that your dog carries two alleles for degenerativemyelopathy and may develop degenerative myelopathy (affected). Not all dogs with A/A results will develop DM.
Symptoms:
Degenerative myelopathy initially affects the back legs and causes muscle weakness and loss, and lack of coordination. These cause a staggering affect that may appear to be arthritis. The dog may drag one or both rear paws when it walks. This dragging can cause the nails of one foot to be worn down. The condition may lead to extensive paralysis of the back legs. As the disease progresses, the animal may display symptoms such as incontinence and has considerable difficulties with both balance and walking. If allowed to progress, the animal will show front limb involvement and extensive muscle atrophy. Eventually cranial nerve or respiratory muscle involvement necessitates euthanasia. Progression of the disease is generally slow but highly variable. The animal could be crippled within a few months, or may survive up to three years or more.
Causes:
The etiology of this disease is unknown. Recent research has shown that a mutation in the SOD1 gene is a risk factor for developing degenerative myelopathy in several breeds. Mutations in SOD1 are also associated with familial amyotrophic lateral sclerosis (Lou Gehrig’s disease) in people.
Known causes of spinal cord dysfunction should be excluded before accepting the diagnosis of degenerative myelopathy; disc disease (protrusions) or spinal cord tumours can cause compression of the spinal cord with similar signs to degenerative myelopathy.
Treatment:
Degenerative myelopathy is a non-reversible, progressive disease that cannot be cured. There are no treatments that have been clearly shown to stop or slow progression of DM.
Our philosophy about DM: With only a small percentage of the boxers testing clear for DM, moving toward a clear population of boxers is a conundrum for many breeders. We do not want to raise At Risk puppies; yet if we breed to only the dogs that are clear, we will most certainly lock other deadly genetic traits into the breed as a whole.
DM is often called "an old dog's disease". We watched our beautiful Uncle Petie wither away and die from DM, so we have known the suffering that goes along with this unfortunate disease. We breed only clear dogs whenever possible, and we hope that our breeding choices and support of natural rearing protocols will contribute to the slow process of removing this from our breed. We respect the choices made by other breeders as well, as this is a very personal decision that must be made with consideration for the preservation of our breed as a whole.
When I first started breeding boxers in 1972-ish, nothing was known about DM. In 2008, a genome test was developed that we began using to help us as breeders. Dogs that have clinical signs or a presumptive diagnosis of DM have tested as genetically affected. At that time, a relatively high percentage of dogs in several breeds (including Boxers, Pembroke Welsh Corgis, Chesapeake Bay Retrievers and Rhodesian Ridgebacks) were tested with the predisposing mutation. It is important to note that there are a large number of dogs that have tested as genetically affected, but are reported as clinically normal by their owners. This meant that a dog testing with two abnormal alleles for DM would not necessarily express the disease. But that dogs testing with those two abnormal alleles for DM would be categorized as "At Risk" of expressing the disease. And although the gene test was not diagnostic of DM, we came to understand that only those dogs who tested as "At Risk" would ever get the disease. For many years, it was very difficult to find quality boxers who were not carrying at least one allele for DM, and though those dogs were simply carriers, and they would never get the disease... when combined with another dog who was a carrier or At Risk, all boxer breeders were producing At Risk puppies in many of those litters.
As a breeder myself, finding a way to breed DM out of our litters was a constant challenge, as so many boxes need to be checked when choosing potential dogs to breed together. With our two biggest causes of early death in boxers being cancer and cardiomyopathy, often DM had to take a back seat to selections made to keep those possible health issues from arising. When boxers first began being tested for DM, only 17% were genetically clear. At this point in 2024, 20% are clear, 30% are carriers, and 50% are genetically At Risk. If you look at the statistics published at OFA, boxers are the third highest breed in "At Risk" statistics. Of course, realize that not all boxers are tested, and of those that are, not all are published to OFA (which costs the breeders money to do.) So in my humble opinion, our stats are probably worse than what we see published. (I think it is human nature to assume that people who get results they don't like usually are inclined not to publish them like we do. But you can check any specific breeder's habits in this area by checking their particular dogs. Usually you can just type in their kennel name and verify that the dog you are looking at is theirs, then check for DM results on that dog. If they aren't publishing results to OFA, ask for the raw copies of the health tests you are interested in. This is what a properly tested boxer on OFA should look like. This is what the raw DM results look like. This is what a DM certification looks like.)
When we make breeding decisions that only produce DM Clear or DM Carrier, our clients are protected from ever experiencing what Cali is experiencing. It is only the DM At Risk puppies you need be concerned about. We do not make compromises in other areas in order to produce only carriers or clear puppies, as it is the picture as a whole that matters. And though we are show breeders, we are now finding that we do not need to compromise on substance or breed standard in order to avoid this terrible disease for our clients. We have driven as far as 4800 miles to get to just the right stud dog to fulfill all those requirements, and will continue to do so.
This beautiful girl, Cali, is just one example of the final stages of DM. After three years of being cognitively able and wanting to play, she finally had to be euthanized because this disease is currently fatal with no treatments. And though the disease itself causes no pain, the suffering it inflicts on the dog and the family are simply beyond words. Again, a dog may be genetically "At Risk" with two DM alleles, and never express the disease. But if they live long enough and don't succumb to something else, research shows that they are very likely to suffer this end of life scenario. My eternal thanks to Danielle Tomaselli for sharing her beautiful Cali with the world to bring awareness to the terrible damage that DM causes. So much love to you Danielle.
DM is often called "an old dog's disease". We watched our beautiful Uncle Petie wither away and die from DM, so we have known the suffering that goes along with this unfortunate disease. We breed only clear dogs whenever possible, and we hope that our breeding choices and support of natural rearing protocols will contribute to the slow process of removing this from our breed. We respect the choices made by other breeders as well, as this is a very personal decision that must be made with consideration for the preservation of our breed as a whole.
When I first started breeding boxers in 1972-ish, nothing was known about DM. In 2008, a genome test was developed that we began using to help us as breeders. Dogs that have clinical signs or a presumptive diagnosis of DM have tested as genetically affected. At that time, a relatively high percentage of dogs in several breeds (including Boxers, Pembroke Welsh Corgis, Chesapeake Bay Retrievers and Rhodesian Ridgebacks) were tested with the predisposing mutation. It is important to note that there are a large number of dogs that have tested as genetically affected, but are reported as clinically normal by their owners. This meant that a dog testing with two abnormal alleles for DM would not necessarily express the disease. But that dogs testing with those two abnormal alleles for DM would be categorized as "At Risk" of expressing the disease. And although the gene test was not diagnostic of DM, we came to understand that only those dogs who tested as "At Risk" would ever get the disease. For many years, it was very difficult to find quality boxers who were not carrying at least one allele for DM, and though those dogs were simply carriers, and they would never get the disease... when combined with another dog who was a carrier or At Risk, all boxer breeders were producing At Risk puppies in many of those litters.
As a breeder myself, finding a way to breed DM out of our litters was a constant challenge, as so many boxes need to be checked when choosing potential dogs to breed together. With our two biggest causes of early death in boxers being cancer and cardiomyopathy, often DM had to take a back seat to selections made to keep those possible health issues from arising. When boxers first began being tested for DM, only 17% were genetically clear. At this point in 2024, 20% are clear, 30% are carriers, and 50% are genetically At Risk. If you look at the statistics published at OFA, boxers are the third highest breed in "At Risk" statistics. Of course, realize that not all boxers are tested, and of those that are, not all are published to OFA (which costs the breeders money to do.) So in my humble opinion, our stats are probably worse than what we see published. (I think it is human nature to assume that people who get results they don't like usually are inclined not to publish them like we do. But you can check any specific breeder's habits in this area by checking their particular dogs. Usually you can just type in their kennel name and verify that the dog you are looking at is theirs, then check for DM results on that dog. If they aren't publishing results to OFA, ask for the raw copies of the health tests you are interested in. This is what a properly tested boxer on OFA should look like. This is what the raw DM results look like. This is what a DM certification looks like.)
When we make breeding decisions that only produce DM Clear or DM Carrier, our clients are protected from ever experiencing what Cali is experiencing. It is only the DM At Risk puppies you need be concerned about. We do not make compromises in other areas in order to produce only carriers or clear puppies, as it is the picture as a whole that matters. And though we are show breeders, we are now finding that we do not need to compromise on substance or breed standard in order to avoid this terrible disease for our clients. We have driven as far as 4800 miles to get to just the right stud dog to fulfill all those requirements, and will continue to do so.
This beautiful girl, Cali, is just one example of the final stages of DM. After three years of being cognitively able and wanting to play, she finally had to be euthanized because this disease is currently fatal with no treatments. And though the disease itself causes no pain, the suffering it inflicts on the dog and the family are simply beyond words. Again, a dog may be genetically "At Risk" with two DM alleles, and never express the disease. But if they live long enough and don't succumb to something else, research shows that they are very likely to suffer this end of life scenario. My eternal thanks to Danielle Tomaselli for sharing her beautiful Cali with the world to bring awareness to the terrible damage that DM causes. So much love to you Danielle.
