Your shih tzu may be shaking because it is cold, excited, anxious, or trying to gain your attention.
If your shih tzu only shakes when the temperatures drop, consider giving your pet a coat, sweater, or covering him with a blanket especially at night.
If he shakes when he’s happy or excited, he’ll calm down eventually, at which point, it’s time to reward him. This will prevent the shaking from becoming an uncontrollable habit.
If your shih tzu shakes when he’s afraid or anxious (for example, during thunderstorms), reassure him and divert his attention with toys or games. Also, remember that your pooch will be reading your mood, so if you remain calm and relaxed, you’ll be helping him.
In rare cases, your shih tzu may be shaking due to illness or pain. If you’re at all unsure about why he’s suddenly behaving in this way, a trip to the vet may be needed to identify the cause.
Trembling could be a sign of arthritis or muscle pain due to old age. A veterinarian will be able to diagnose the cause and offer treatment.