This WaltF who started this thread. I'm pasting below (rather long) messages I sent to our children (and a few friends) about my wife, their mother or step mother. I hope they may give useful ideas to others. Her name is removed. The first message (A) was sent two years ago. The second (B) is recent:
(A) Alzheimer’s Destruction of Nerves; Functional Losses.
Most of us know that Alzheimer's disease is found in many older people. But we don't know much about what happens to the brain to bring about the losses of memory, physical stability and basic functions.
I want to tell you a little bit about what happens to brain neurons (nerves cells) in Alzheimer’s. Knowing this helps me remember that the victim is not responsible for the severe changes caused by it. It helps me to try to remain understanding and compassionate.
(At the bottom here is a link to a pretty good, brief article with diagrams on the neurons)
(Also, a link to the stages of Alzheimer’s—there is a lot of variation from person to person)
Two of the major "actors" in Alzheimer's are called beta-amyloid (pronounced "bay-tuh-am-uh-loid") and Tau (sounds like the tow in towel). Little or no beta-amyloid is found in normal brains. With Alzheimer's it accumulates, lodging at the interacting parts (synapses) of two brain neurons. [The human brain contains 100 billion long neurons that transfer signals at 100 trillion synapses]. That accumulation of beta-amyloid blocks signal transmission at those synapses so that some function is lost. As it continues to accumulate those neurons die. Tau is a normal component of neurons. It acts to help keep a neuron elongated, or relatively straight, so that it touches other neurons throughout the brain and forms synapses with them. In Alzheimer's something disrupts this normal Tau function. It collapses into tangles causing the nerve to collapse, lose its synapses, and die.
This destruction of nerves continues for years. Along with their loss are constant losses of cognitive functions and of physical abilities. These include memories of recent experiences, of old memories, of normal body stability, of how to care for oneself, and eventually of the ability to swallow properly (often leading to death from aspiration pneumonia).
The enormity of this nerve death is seen in patients dying from Alzheimer’s--their brains are about 30% of normal size.
Love, Walt
Inside the Brain: A tour of how the mind works
https://www.alz.org/alzheimers-dementia/what-is-alzheimers/brain_tour_part_2
The Seven Stages of Alzheimer’s
https://act.alz.org/site/DocServer/sevenstages.pdf?docID=16881
(B) Here’s an update on how your Mom is doing— from our physician, from me, and from a good friend.
From our new Gerontologist/PCP: He said she’s doing very well compared to most other Alzheimer’s patients with her length of time from initial diagnosis (5 1/2 years)
From Me: In general her memory continues to be worse— new memories often gone after 30 secs or so. Using gadgets correctly, such as the microwave, is almost impossible. Many of our discussions are labored. She is easily distracted, going from an unfinished task to a different one—totally unaware. She gets frustrated, helping me in the kitchen or with other tasks, when she cannot remember what the next step is or where the next needed thing is. We spend a lot of time looking for things around the house that are “lost“.
She sees many things with a kind of whimsical eye, things that are not real to me: a cloud formation is amazing, like nothing she’s ever seen; a row of five houses along a neighborhood street have all been freshly painted and she concludes that they were given paint by the city to do it (they were painted about 20 years ago).
She does continue to take care of herself —dressing, personal hygiene etc. She still cleans up after meals and does the laundry. But these are now often delayed or forgotten.
Comprehension, and retention, of information of a movie watched or a book read by her or to her by me is very poor. But we still do the NYT crossword (mostly Mondays) about three times a week. She gets about 30% of the words, some of them I would never get. She gets a bit frustrated, but we mostly enjoy it.
She still understands quite well the difficult changes that are happening in her. It is very frustrating for her. Despite my efforts to treat her to the contrary, she often feels that she’s a great burden to me and “you should put me away somewhere“. It is wrenching.
After using a 4-wheel walker for a few months she has become steadier on her feet. Now she walks 1-1.5 miles 3-4 times a week, alone with a walking stick and Buddie on a leash (I follow her progress on my phone from home).
Despite her difficulties, she continues to do well in social situations with family and friends.
Please know that much of our time together is pleasant and pleasurable.
From a Good Friend: She did well in her familiar environment of having company to dinner. She found a vase for flowers we brought, arranged them and went outside for greenery to add to the vase. She did this confidently and with ease.

I could have written your post myself. Our situations have much in common. Deaf husband who wants to help but gets in the way. Old Chihuahua that doesn't like husband, who can't remember to Just Leave Him Alone. It's getting harder to be away from home for more than an hour or so, though he still drives to his favorite places. I read, read, read. Lots of mysteries and novels, some biography and history. I'd be lost without books, email, and this site. Upcoming first appointment with neurologist that husband doesn't understand the reason for. Steady decline in cognitive function. What does the future hold? I was recently diagnosed with an aortic aneurysm and should avoid stress, which means I shouldn't blow up at my husband. You know how hard that is, especially when he can't hear so I have to shout. I'm right there with you.

Wow this is me, except my dog is 13 and still ok. And he’s more his dog so it will be really hard on him when…I need this reminder to keep answering and not to yell.