As my stepdaughter phrase it this way: "The more he drinks, the better he thinks." When he doesn't drink enough, we've had 3 issues: His blood pressure drops too low, he once got pneumonia, and his confusion increases.
The one thing I've found that works is giving him popsicles. Any other suggestions?
Fruit or vegetable juice with his meals, the occasional glass of beer, soda or sparkling water?
Don't forget fruits and vegetables are mostly water, soup is also a great way to add fluids.
Keep a small glass of something always at his elbow in a travel mug, or some people do better with a straw.
And - If you have ever noticed him coughing or having any difficulty when drinking he may be having problems with his swallow and needs an evaluation, if so he will need his fluids thickened (there are products available for that)
I don't think she drinks more than 24 oz in a day. And that's just Coke. Maybe 4 oz of OJ, but primarily 2 cans of Coke and that's it.
It's a battle I long since gave up on. She's 90 and barely moves in a day. She's not sweating, and she's used to being fairly dehydrated.
We did give daddy popsicles round the clock at the end of his life. He too was catherized, and bedbound.
I'd say keep trying with the fluids, if you have that much say in mom's food intake. I know when I am dehydrated, I will get a migraine.
I've gone through this with my mom and she became so severely dehydrated that she nearly died in mid April from it along with having COVID.
The majority of elderly people don't like to drink water and if Alzheimer's is involved they often don't remember to do it.
Once released from the hospital and rehab. I began to buy her V8 Plus Energy drinks for some fluids and now provide her with the "Nestle Pure Life" slightly flavored waters which both my mom and I drink. They come in four flavors. If you want to stick to just water, I've added lime slices or orange slices in lieu of the traditional lemon slices. It's good and refreshing.
Our brain is made up of approximately 72% + water and therefore is very important for all of us to drink it in order to help us with our ability to think more clearly.
Good luck!