The spinal cord is responsible for carrying signals between the brain and the body, controlling voluntary movement, coordination, and reflexes. In dogs affected by DM, the nerve fibers in the spinal cord gradually deteriorate, especially in the region that controls the hind limbs. This results in progressive weakness and loss of motor function over time.
Clinical signs of DM typically appear in adult to senior dogs, usually after 5 years of age, although onset can vary depending on breed and genetic factors. The earliest signs are often subtle and may include mild dragging of the hind paws, unsteady gait, or difficulty rising. One of the classic early indicators is knuckling of the hind feet, where the dog may scrape the top of the paw while walking.
As the disease progresses, hind limb weakness becomes more pronounced. Dogs may develop a wobbly or swaying gait (ataxia), difficulty maintaining balance, and reduced coordination. Muscle wasting in the hind limbs is common due to lack of nerve stimulation. Eventually, dogs may lose the ability to support weight on the hind end and require assistance for walking or mobility.
In later stages, DM can progress to involve the forelimbs as well, although the hind limbs are typically affected first and most severely. Importantly, DM is not considered a painful condition, but it leads to significant mobility impairment and reduced quality of life as the disease advances.
The DM DNA Health Test is designed to detect the mutation in the SOD1 gene associated with Degenerative Myelopathy. The test is simple, safe, and non-invasive, usually performed using a cheek swab or blood sample. The DNA is analyzed in a specialized laboratory to determine whether the dog carries zero, one, or two copies of the mutation. Because genetic information remains unchanged throughout life, testing can be done at any age, including before symptoms appear.
Results are generally reported as:
- Clear (Normal): The dog does not carry the SOD1 mutation and is not expected to develop DM.
- Carrier: The dog carries one copy of the mutation but typically does not show clinical signs; however, it can pass the mutation to offspring.
- At Risk (Homozygous Affected): The dog carries two copies of the mutation and is at increased risk of developing clinical signs consistent with DM.
It is important to note that not all dogs with two copies of the mutation will develop the disease, as other genetic and environmental factors may influence expression. However, they are considered at significantly higher risk.
Genetic testing for DM is extremely valuable for breeders, veterinarians, and dog owners. For breeders, it helps reduce the frequency of the SOD1 mutation in breeding populations by avoiding at-risk pairings while maintaining genetic diversity. For dogs used in breeding programs, responsible selection based on test results helps improve long-term neurological health in future generations.
For dog owners, early knowledge of genetic status allows for proactive planning. While there is currently no cure for DM, supportive care such as physiotherapy, mobility support devices (wheel carts), controlled exercise, and home adaptations can help maintain quality of life for as long as possible.
The Degenerative Myelopathy (DM) Health Test is a reliable genetic screening tool that supports responsible breeding practices, early risk identification, and improved long-term neurological care in dogs.
