Spontaneous lower motor neuron disease in rabbits (oryctolagus cuniculus).

Spontaneous neurologic disease was observed in 6 to 8-week-old rabbits. Both males and females from several different litters were affected but all were sired by the same male. Clinically, the disease was characterized initially by posterior weakness and incoordination which progressed to tetraplegia within 3--4 weeks. With light microscopy there was neuronal degeneration and loss within the ventral horns of the spinal cord and brain stem and type-II fiber atrophy of skeletal muscles. Ultrastructurally the neuronal degeneration was characterized by accumulations of 100 A neurofilaments within the perikaryon. These findings are compared to diseases with neurofibrillary accumulation in animals and man.