Spinocerebellar Ataxia with Myokymia and/or Seizures in Dogs

Category: Nervous System & Behavioral
Breeds documented: 4
Published sources: 6

Overview

This inherited nervous system disorder causes ataxia, meaning poor coordination and balance. The walking pattern may become bouncy or unusually high-stepping and generally worsens over time. Some dogs also develop myokymia, visible rippling muscle twitches, or episodes of severe muscle stiffness. Seizures occur in some affected dogs, but the combination of signs varies. Changes in a gene called KCNJ10 underlie several described forms.

Signs to watch for

Bouncy or high-stepping walking with poor balance.
Rippling muscle twitches visible beneath the skin.
Episodes of marked stiffness, sometimes with collapse.
Repeated face rubbing before some episodes.
Seizures in some affected dogs.

Poor coordination often starts between 2 and 6 months of age, depending on the form.

Emergency Go to an emergency vet now if your dog becomes rigid and collapses.

Diagnosis and tests

Vets combine the dog's age, neurological examination and pattern of signs with DNA testing for the relevant KCNJ10 variant. A specialist may record muscle electrical activity to investigate visible twitching. A negative result for one variant does not exclude other inherited causes of poor coordination.

Breeds with documented risk

4 breeds

By breed size

2 Toy
2 Small

ChihuahuaToy · Toy Group
Toy Fox TerrierToy · Toy Group
Smooth Fox TerrierSmall · Terrier Group
Tenterfield TerrierSmall

Inheritance

Not yet known
None of the sources we use states how this is inherited in dogs yet.

We've gathered what published sources say about this condition, so you can talk it through with your vet. It isn't veterinary advice: you and your vet know your dog best.