Cerebellar Ataxia 2 (Belgian Shepherd Type) is a progressive, early onset, inherited neurologic disease affecting the Belgian Sheepdog. Symptoms usually present as early as the first four weeks of life and progress quickly. Affected dogs are unable to regulate potassium in the central nervous system. Potassium is critical for proper nerve function. These dogs have difficulty controlling leg movements and keeping their balance. Owners may observe dogs stumbling, staggering, circling, pacing, experiencing tremors, and falling. Some dogs may present with seizures and blindness. Most affected dogs either die or are euthanized within weeks after presentation due to severity and progression of clinical signs.