If your dog shivers excessively or suddenly starts shaking it may be cause to consult your veterinarian (as sudden onset can be a symptom of pain or a nervous disorder) but if full body shivering or a foot or leg that trembles is something you've noticed from puppyhood then your dog's shaking is probably nothing to worry about. Although not explained, it has been noted that trembling legs occur more often in terriers and white dogs
