Neuronal ceroid lipofuscinosis 5 (NCL5) is a lysosomal storage disease affecting Border Collies. 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 nervous system disorders. Affected dogs typically present between 15 and 20 months of age with behavioral changes. Symptoms initially include non-responsiveness to commands, loss of interest in play or other dogs, irrational fears, hallucinations, disorientation and aggression. Symptoms become more frequent and severe over time and may include Ataxia, falling, seizures, aimless wandering, abnormal gait, lethargy and vision loss. Dogs with this disease rarely live beyond 32 months of age.