Presumed immune-mediated cerebellar granuloprival degeneration in the Coton de Tulear breed

An unusual form of cerebellar granuloprival degeneration was observed in th ree male Coton de Tulear puppies between 12 and 14 weeks of age from differ ent litters showing progressive cerebellar signs beginning at 8 weeks after birth. Pathological examinations revealed a shrunken cerebellum. Histopath ologically the granular cells were diminished or almost completely absent, some 'torpedos' of Purkinje cells were present. There was a marked gliosis, and occasionally small inflammatory foci were present. A marked diffuse T cell infiltration (CD3(+) cells) occurred in the lesions, B cells did not a ppear. CD18 staining showed an upregulation of microglial cells at the lesi on site. Histopathologically the lesions resembled paraneoplastic cerebella r degeneration which is caused by an autoimmune mediated T cell reaction. T his congenital condition in the Coton de Tulear dog breed could be based on a genetically defined immune defect leading to autoimmune destruction of t he granular cells. (C) 2000 Elsevier Science B.V. All rights reserved.