My Shih Tzu is one year old. At times for no reason
she shakes as if she is either cold or scared. As
warm as it is I know she can’t be cold and there
has been nothing that has happened at the time for
her to be scared. I sit and hold her close and
then in just a few minutes she seems to be ok. Is
there anything I should be concerned about?
Probably not. Trembling is a very common–and very nonspecific–behavior in dogs.
You are correct that cold and fear are two of the most frequent causes of trembling. Other causes include but by no means are limited to excitement, hunger, muscle fatigue, nausea and transient harmless nerve impulses.
However, there are some more serious causes of trembling. Low blood sugar, liver shunts, certain forms of epilepsy and electrolyte imbalances are on the list.
If your dog is eating, drinking, and eliminating normally the odds that something serious is going on are slim. Nonetheless, I think a vet visit is in order to confirm this.