What causes a cats head to shake or tremble often?
It is neurological. Your brother should have informed you of any pre-existing conditions before he left his cat in your care. Research FELINE CEREBELLAR HYPOPLASIA. The head shaking and trembling are minor symptoms. There are varying degrees of severity. I would try to contact your brother first. I would only suggest contacting a vet if you sense that there is an emergency. The cat seems lethargic, vomiting, not eating. Those can be signs of poisoning which will affect the neurological system. If your brother did not say anything and the cat seems otherwise happy, content, eating, sleeping ok, playing, then the head trembling and shaking might be a static condition; some pre-existing neurological condition. I hope that this helps.
