Canine degenerative myelopathy — sometimes called chronic degenerative radiculomyelopathy — is an incurable, progressive disease of the spinal cord that's been compared to ALS in humans. It typically starts with subtle rear-end weakness and progresses over months to years into full hind-limb paralysis. There's no treatment; once symptoms appear, the disease only moves in one direction.
The reason it matters in the German Shepherd world specifically is that DM is genetic, and the breed has historically been a higher-risk population. The good news: it's almost entirely preventable through responsible breeding.
What causes it
DM is linked to a mutation in the SOD1 gene. Dogs inherit two copies of every gene — one from each parent — and the SOD1 mutation acts in an autosomal recessive pattern with incomplete penetrance. In plain English: a dog needs two copies of the mutation to be at risk, and even then, not every affected dog will develop clinical signs. But every "at risk" dog can pass copies of the mutation to its offspring.
DNA testing classifies a dog into one of three results:
• Clear / Normal (N/N) — two normal copies. Cannot develop DM and cannot pass the mutation.
• Carrier (N/M) — one normal copy, one mutated. Will not develop DM, but can pass the mutation to puppies.
• At Risk (M/M) — two mutated copies. May develop DM and will pass a mutated copy to every puppy.
How Kaiser screens for it
We DNA-test every dog in our breeding program for degenerative myelopathy before they're ever bred. We do not breed an "at risk" (M/M) dog. When pairing a clear dog with a carrier, the outcome is straightforward: no puppy will be at risk for developing DM, though some may be carriers themselves and need to be paired with clear dogs in future generations.
Test results are posted on each dog's profile page on our site. If you're considering a Kaiser puppy and DM status is important to you, ask — we'll show you the actual lab paperwork.
What to ask any breeder
If you're evaluating breeders, the question is simple: "Have both parents been DNA-tested for degenerative myelopathy, and what were the results?" A breeder who can't answer that question — or who hand-waves it — isn't being responsible with the breed.