We began the present study by genotyping 6 neurologically affected dogs including three ataxic Smooth-Haired Fox Terriers, two ataxic Toy Fox Terriers, and a Danish-Swedish Farm Dog with neuromyotonia for the mutations associated with SAMS (KCNJ10:c.627C>G) and LOA (CAPN1:c.344G>A) to investigate whether the mutant alleles are associated with neurologic disease in these breeds that are related to the Russell group terriers. Here, CAPN1 is linked to Isaacs syndrome.