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Degenerative Myelopathy (Degenerative Damage to the Spinal Cord’s Neural Pathways) in Dogs

Occurrence: very rare
Location of illness: Back/Tail

Degenerative myelopathy (DM) is a progressive neurological disease that leads to damage of the nerve pathways in the spinal cord of dogs, ultimately leading to paralysis of the hind legs.

The most important facts at a glance

Degenerative myelopathy is a progressive neurological disease that primarily occurs in older dogs of certain breeds such as the German Shepherd and the Boxer. It is similar to amyotrophic lateral sclerosis (ALS) in humans and leads to a degeneration of the white matter in the spinal cord, which causes loss of motor coordination. Genetic factors, especially a mutation in the SOD1 gene, play a significant role in the development of the disease. A genetic test can help confirm the presence of this mutation, but not all dogs with the mutation develop the disease.

Symptoms include uncoordinated movements, weakness, and muscle wasting in the hind legs, while complete paralysis can also occur in advanced stages. Diagnosis is made by excluding other causes and through genetic testing. There is no cure, but supportive measures such as physiotherapy, walking aids, and nutritional supplements can improve quality of life.

The prognosis is unfavorable, as the disease can lead to complete paralysis within six months to two years. Preventive measures focus on genetic testing and responsible breeding to reduce the risk in future generations. Research is currently investigating genetic and therapeutic approaches to slow or stop the progression of the disease, with stem cell therapy considered promising.

Causes

Degenerative myelopathy is a disease that mainly occurs in older dogs, especially in certain breeds such as the German Shepherd, Pembroke Welsh Corgi, Boxer, and Rhodesian Ridgeback. The disease begins in middle to old age, typically from around eight years of age.

From a scientific perspective, DM is comparable to amyotrophic lateral sclerosis (ALS) in humans. It leads to a progressive degeneration of the white matter in the spinal cord. This degeneration affects the myelinated axons responsible for transmitting nerve impulses, leading to a loss of function.

The exact cause of degenerative myelopathy is not yet fully understood. However, it is believed that genetic factors play a significant role. A defect in the superoxide dismutase 1 (SOD1) gene has been identified as a significant risk for developing the disease. This genetic marker can be detected in affected dogs and carriers, indicating a hereditary component.

Environmental influences and other genetic factors could also play a role in triggering or exacerbating the disease, although these connections are not yet fully understood. Research in this area is ongoing to develop a better understanding of the pathogenesis.

Symptoms

Very common symptoms:

Common symptoms:

Rare symptoms:

Degenerative myelopathy usually begins insidiously with slight signs of weakness in the hind legs. This can manifest as a wobbly or unsteady gait that progresses over time.

Over time, the weakness can develop into complete paralysis of the hind legs. Dogs may also have difficulty getting up or climbing stairs. In advanced stages, the front legs may also be affected.

Other symptoms may include a loss of proprioception, i.e. the ability to recognize the position of one’s limbs in space, as well as a loss of bladder and bowel control. Pain is usually not a direct symptom of the disease, as the nerve pathways that transmit pain signals are not primarily affected.

Diagnosis

The diagnosis of degenerative myelopathy is made by excluding other possible causes for the neurological symptoms. This includes a complete neurological examination, imaging procedures such as X-rays, MRI or CT, and, if necessary, a cerebrospinal fluid examination.

A genetic test can be performed to confirm the presence of the SOD1 mutation associated with DM. While the presence of this mutation supports the diagnosis, it is not decisive on its own, as not all dogs with the mutation develop the disease.

Electrophysiological tests can also be used to assess nerve conduction to determine the degree of neurological impairment.

Therapy

Currently, there is no cure for degenerative myelopathy, and treatment focuses on supporting and improving the quality of life of the affected dog.

Physiotherapy can help maintain muscle mass and improve mobility, which can slow the progression of the disease. Regular exercises specifically tailored to the dog’s needs can also be beneficial.

Additional supportive measures may include the use of walking aids or wheelchairs to promote the dog’s mobility. Supplements and certain medications can be used to support neurological health, although their effectiveness may vary.

Prognosis and follow-up care

The prognosis for dogs with degenerative myelopathy is unfortunately unfavorable. The disease generally progresses within six months to two years after the onset of the first symptoms, ultimately leading to complete paralysis.

The dog’s quality of life can be improved through supportive measures such as physiotherapy and mobility aids. The decision on the right time for humane euthanasia depends on many factors, including the dog’s quality of life and the owners’ ability to provide the necessary care.

Prevention

The prevention of degenerative myelopathy focuses primarily on genetic testing and responsible breeding. By identifying carriers of the SOD1 mutation, breeders can make informed decisions to reduce the risk of the disease in future generations.

Some breeding associations and organizations recommend genetic testing for dogs of certain breeds that are susceptible to DM. This allows breeders to avoid pairings that could increase the risk of producing affected offspring.

There are currently no specific environmental measures that have been shown to reduce the risk of developing DM in dogs. Nevertheless, generally promoting neurological health through a balanced diet and regular exercise could be beneficial.

Outlook on current research

Degenerative myelopathy (DM) is a progressive neurological disease that primarily affects older dogs. It affects the white matter of the spinal cord and leads to a progressive loss of motor coordination. In recent years, research has made significant progress in better understanding the genetic and molecular basis of this disease.

A major focus of current research is on genetic predisposition. A mutation in the SOD1 gene has been found to be strongly associated with the occurrence of DM. This genetic link has made it possible to develop DNA tests that can determine the risk of the disease in certain dog breeds. Based on these findings, researchers are working to develop genetic therapies that could potentially slow or stop the progression of the disease.

Another significant area of research is the development of new therapeutic approaches. Currently, there is no cure for DM, but various experimental treatments are being tested. These include neuroprotective drugs that could slow the degeneration of nerve fibers, as well as physical therapies aimed at maintaining the mobility of affected dogs.

Stem cell therapy is also being investigated as a promising approach. Animal studies have shown that administering stem cells into the spinal cord can promote the regeneration of nerve tissue. Although these therapies are still in the early stages of development, they offer hope for future treatment options.

In addition to genetic and therapeutic research, scientists are also investigating the environmental factors that could influence the progression of DM. Factors such as diet, exercise, and lifestyle could play a role in modulating disease severity. Long-term studies that take these factors into account could help develop preventive strategies that reduce the risk or progression of the disease.

Collaboration between veterinarians, geneticists, and neurologists is crucial for progress in this area. Interdisciplinary research approaches make it possible to better understand the complex mechanisms of DM and to develop innovative solutions. While a complete cure for degenerative myelopathy is still in the future, advances in research are promising and could one day lead to more effective treatments.

Frequently asked questions (FAQs)

What is Degenerative Myelopathy? Degenerative myelopathy is a progressive neurological disease that affects the nerves in the spinal cord of dogs, leading to a loss of motor coordination.
Which dog breeds are most commonly affected? German Shepherds, Welsh Corgis, Boxers, and other large dog breeds are most commonly affected. However, the disease can also occur in other breeds.
What are the early signs of Degenerative Myelopathy? The first signs are often subtle changes in the dog’s gait, such as stumbling or difficulty getting up. As it progresses, it can lead to complete paralysis of the hind legs.
How is Degenerative Myelopathy diagnosed? Diagnosis is usually made by excluding other diseases that could cause similar symptoms, as well as through genetic tests that can detect the SOD1 mutation.
Is there a cure for Degenerative Myelopathy? There is currently no cure for DM. Treatment focuses on supporting quality of life through physiotherapy and, if necessary, the use of aids such as wheelchairs.
Can medications cure the disease or stop its progression? There are currently no medications that can cure DM. However, some medications may help relieve symptoms or slightly slow the progression of the disease.
How can I help my dog with DM? Regular physical therapy, a balanced diet, and adapting the living environment can help improve the quality of life of a dog with DM. The use of special aids can also be useful.
Is the disease painful for my dog? Degenerative myelopathy does not cause direct pain, as the disease affects the nerves responsible for movement, but not pain sensation. However, secondary problems, such as pressure sores, can cause pain.
Can I reduce the risk of my dog developing DM? Since DM has a genetic component, it is difficult to eliminate the risk completely. However, responsible breeding management and genetic testing can reduce the risk in the population.
What current research approaches are there to combat DM? Research focuses on genetic therapies, neuroprotective drugs, stem cell therapies, and the study of environmental factors to slow or prevent the progression of the disease.