Equine neuronal ceroid lipofuscinosis

Neuronal ceroid lipofuscinosis (NCL) is an inherited, neurodegenerative dis order with fatal outcome in humans. It has also been described in some anim al species; this is the first report of NCL in equines. Three horses showed developmental retardation, slow movements and loss of appetite at the age of six months. Neurological symptoms, as well as visual failure in one case , were noticed at the age of 1 year. Due to slowly progressing deterioratio n, euthanasia was indicated 1.5 years after onset of conspicuous behavior. At necropsy, slight flattening of the gyri and discoloring of the brain was noticed. Histopathology revealed eosinophilic, autofluorescent material in the perikarya of neurons throughout the brain and spinal cord. Identical m aterial was found in neurons of retina, submucous and myenteric ganglia, as well as in glial cells. Immunohistochemistry, using antiserum against subu nit c of mitochondrial ATP synthase, showed positive signals in neurons and glial cells. Electron microscopical studies revealed fingerprint profiles mixed with rectilinear structures in markedly enlarged lysosomes of neurons and renal tubules, and rectilinear structures mixed with curvilinear bodie s in macrophages and lymphocytes of lymph nodes. Thus, our study presents t he first occurrence of lysosomal storage disease in horses, further charact erized by immunohistochemical and electron microscopical investigations as NCL.