your dog may shiver because...
if you have another animal in the house they sometimes get frightened of them and sometimes because you give the other animal more attention and he might feel lonely.
...
It could be because they are cold. People often mistake the "shiver" for a tremble tho. In small dogs, like chihuahuas, its usually a neurotic condition or flaw that comes from inbreading. It can...
Dogs get the shivers by a couple of things that include: coming from a freezing cold environment into a warm environment immediately, another way is if your dog is eating any toxic things like for...