I have a dog walker and the carers also keeo an eye on the dog. He is good company for my dad and a good guard dog as he lives on his own

Hi - when I moved my parents to the town where I live they came with their 2 year old yellow lab. Poor dog was overweight and had never been walked or socialized with other dogs.
First thing I did was take Nikki (dog) to the vets for a check up and brought my parents. That way, it was someone else telling them the dog needed to lose weight. The Vet put her on weight loss food.
The 2nd thing I did was portion out the food for the week. 1 cup in a plastic baggie x 3 bags per day, one cup for breakfast, lunch and dinner. I hid all dog food except for the 3 bags per day, one day at a time. My parents could still feed the dog (and they really didn't know how much it worked out to each day), so they were happy.
3rd thing I did was get rid of all treats like Milkbones (which are like feeding the dog Big Macs) and bought freeze dried liver at my local Costco. I portioned out those as well based on the instructions on the bag. I told my parents I bagged everything to make it easier for them and to ensure their dog's food and treats were alway fresh.
As for leaving the dog out too long, look into a timer (egg timer?), that can be set every time the dogs go out. That may help.
4th thing I did was hire a dog walker. One hours walk a day at $15 or less, Monday to Friday. You may also get one who will be happy to trim nails as well.
As for the large dog bags of food, if you can ask someone to help you get the bag where you need it to be (family, neighbor?), then once you have it there and do your portions, that may eliminate lugging it around. We hid the food and treats in a closet that they never went into. I'm sure you have a place in mind already ☺
The main thing is to use your knowledge of your husband's personality to get him to buy in to any changes. Remember he is scared already of the changes that are happening to his brain, and maintaining any familiar habits become even more important.
Finally (and I apologize for the length of my reply), if you haven't already, hook up with your local Alzheimer's Society - their help is immeasurable!
I hope any of this helps, because you are right, pets are so important ❤

My mom's prized possession is her dog Zeus. He gives her something to dote on and take care of. I know the frustration, she feeds him her entire dinner if I turn my back for a minute and then in 10 minutes asks for something to "snack on" I asked her to not let him eat from her plate... response is to dump the plate on the floor... he is spoiled and if i put him in another room or in his crate he cries and whines and that upsets her. My only suggestion is get small dog treats and limit the number per day... or healthy treats like carrots for the dogs make food and treat boxes/bags unavailable by hiding them.

We have a cat, too and I am the one who cares for her. Mom loves the cat and is always overly concerned that Kitty doesn't get enough to eat. Well, Kitty is overweight. Mom sneaks cheese to her when no one is looking. She gets combative if Dad & I try to correct her. The cat food & treats are well hidden, so mom can't reach them. We play with Kitty as often as possible so she doesn't become too obese. There really are no good solutions other than to give Kitty away, and that's not going to happen. Kitty gives both Mom & Dad so much pleasure, especially with Mom starting to decline more rapidly. We just take one day at a time, enjoy life as much as we can, find the humor in everything, and thank God daily for the time we all still have together. 💘

I agreee with @A myALZteam Member. No one says a dog must eat al the regular meal at one time - it makes perfectly good "treats" as do fresh or froze raw veggies. My sweet RAC worries about our dog so much but she is a joy to both of us so I'm not so upset by having to care for her and watch that she not stay out too long. I do agree with the idea of putting locks on the doors. This is something I've done for a number of reasons. There is a small "flip lock" at the top or our front door and the glass door has atop operated lock on the bottom. He really doesn't see either one and would not be able to open them if he did. I use these locks when we are both in the house. It protects him from putting the dog out without my knowing and it protects him also as I think he wold become lost very quickly if he went out alone.