The neuronal ceroid lipofuscinoses are a group of inherited lysosomal storage disorders. Lysosomes are structures in cells referred to as the stomach of the cell that breakdown waste products and other byproducts in the cell. NCL affected dogs lack one of several enzymes necessary for the normal breakdown of certain types of fat or protein in the cells (called lipopigments.) As this "debris" accumulates in neuronal cells (and to a lesser extent in other cells), the animal's mental and motor functions deteriorate.
Dogs with NCL start out as apparently normal and fully functional dogs. Depending on which subtype of NCL they have, they will begin developing symptoms anywhere from 6 months to 4-6 years of age (for the adult onset varieties). NCL is found in both humans and dogs as well as other species and share symptoms that include a progressive loss of mental and physical nervous system functions. These exhibit as mental/intellectual decline and motor disturbance progressing to seizures, motor problems such as lack of muscle coordination, abnormal gait, difficulty balancing, visual disturbances progressing to blindness and behavioral changes including aggressiveness, dementia, aimless wandering behavior with episodes of confusion, depression and ...