My Cat Trembles When Sleeping. Changes in the depth of sleep can also be signs of underlying problems. Remember that felines have a higher body temperature than the human being, around 39 degrees celsius.

It is also possible that trembling or twitching might be caused by a genetic condition and is untreatable, but not dangerous. I have seen my husband flinch and twitch while sleeping so it's perfectly normal. However, not all sleep is the same.