Neuronal ceroid lipofuscinosis 8 (Australian shepherd type) is a lysosomal storage disease affecting Australian shepherds. Affected dogs lack a specific Enzyme necessary for normal cellular metabolism. As a result, there is an abnormal accumulation of waste compounds primarily in the cells of the nervous system, leading to a range of nervous system disorders. In affected dogs poor vision may be noticed as puppies, but by as early as 10-12 months of age symptoms of cognitive decline appear and may include loss of learned behaviors, circling, and pacing. Symptoms progress to blindness, Ataxia, behavior changes such as anxiety and aggression, tremors, sensitivity to touch and sound, and seizures by the time the dog is 2 years of age. Affected dogs are typically euthanized due to disease progression.