Pontine infarction in a dog with unilateral involvement of the trigeminal motor nucleus and pyramidal tract.

An unusual case of unilateral trigeminal neuronopathy in a dog is reported, in which the motor nucleus of the trigeminal nerve and the ipsilateral corticospinal tract were destroyed, apparently by a cerebrovascular accident (stroke). Hemiplegia did not occur. Neuropathological changes are described, including remyelination by Schwann cells in the central nervous system. The case illustrates the importance of central nervous system post-mortem examination when establishing causes of cranial nerve paralysis.