Can you involuntarily commit an adult to a mental health facility?

My aunt has not been well since her second child. Sadly I think she had ppd and it was never addressed. The last 5 months she has become steadily worse. Her husband and her got divorced because she would through major fits if he tried to clean the house. Now she has lost over 40 lbs and weighs about 90. She won't buy food, she is starving her dog as well. She lives in a rat infested place and doesn't even seem to notice the rat droppings or smell. She will not bathe or even change a light bulb.We have cleaned the house, fixed things, made her feed the dog but we don't live in the same town she does. We know that she needs help but since she is an adult we do not know what we can do? Can someone offer some advice?