Neuronal ceroid lipofuscinosis 5 (golden retriever type) is an inherited lysosomal storage disease affecting dogs. Affected dogs lack adequate activity of 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 neurological symptoms. Affected dogs usually present around 12 to 14 months of age with progressive neurological disease beginning with restlessness and changes in behavior. Around this age, loss of coordination, balance issues, or difficulty climbing stairs may also become apparent and may be more pronounced when excited. The disease progresses to include severe incoordination, wide-based stance, tremors, anxiety, agitation, persistent circling or pacing, loss of response to learned commands or behaviors, snapping at air (called “fly-biting”), blindness, aggression, and seizures. Affected dogs typically die or are humanely euthanized by 2 to 3 years of age.