Affected puppies are small at birth and do not develop normally. They initially nurse poorly, but begin nursing sufficiently after several days... At approximately 3 weeks of age, weakness, ataxia, whole-body tremors, wide-based stance with increased extensor tone, and axial muscle weakness with neck ventroflexion is observed. Affected pups do not interact with the dam or littermates and have slow responses to external stimuli... At approximately 4 to 6 weeks of age, affected puppies develop generalized clonic-tonic seizures that quickly become refractory to treatment. They become laterally recumbent with extensor rigidity and opisthotonus, and usually die or are euthanized before 7 weeks of age (Chen et al., 2008).