Q: How can I get husband to be more understanding of my mother’s Alzheimer’s disease?
A: I'm not sure whether or not your mother is living with you or not, but in the case of men, it is always best to approach them with facts, information, reading material and initially leave the emotion out of it.
Based on your question, her condition hasn't affected him emotionally yet. If your mother doesn't live with you and he doesn't have a close connection to her, then you might never really get what you want from him. However, it is absolutely essential that you explain to him how this makes you feel.
It is extremely difficult to watch a loved one, especially one's mother go through the struggle of Alzheimer's. It is painful and sad and you need his support. So do this for yourself. Explain what her condition does to you emotionally and in the clearest terms possible. For example: Tell him that your heart hurts and you need him to be there for you and then actually ask him for his support. Tell him exactly what you need.
Most men will do whatever you ask, but you have to ask and be clear. Perhaps he's feeling overwhelmed and doesn't know how to help you. When I expect my husband to "just know what to do," I'm often disappointed. When I ask; I'm rewarded.