My Dad's caretaker called and says he is showing the first signs of dementia. What are my options?

If your father has the first signs of dementia, depending on the extent, he could still be competent to sign a new POA, if this is what you would want. This way, you would have more control over the situation and could apply for Medicaid for him if he is out of funds. This process takes months, but might be worth being proactive. Especially for future planning if he ever had to go to a facility, you would have control over where he would live. If the state ever took over and appointed a guardian, they could place him anywhere with no choices.

I wondered what the first signs of dementia might be. Older people often have some of the symptoms of dementia, such as forgetting things, but do not have one of the progressive forms of impairment. Could you tell us a little more?

It is not such a bad idea. If he is a wartime vet, you can also call the VA. If you can, contact the county social services where he lives and ask them to do an in home evaluation of him.