Congenital tremor with spongy degeneration of the central nervous system in two puppies.

Two crossbred puppies exhibited a generalized tremor that was accentuated by excitement or voluntary movement. Hypermetria was also present. Neurohistologic examination showed a bilaterally symmetric spongy condition, predominantly of the gray matter in the brain and spinal cord. These two dogs were different, both in their clinical presentation and histologic appearance, from other reported cases of spongy degeneration. The clinicopathologic correlation between spongy degeneration and tremor is unclear. Spongy degeneration should be included in the differential diagnosis of tremor syndromes in puppies.