Your dog is your pet and partner. It is your responsibility to keep your dog healthy. Address health issues when they first appear, not later. Its the humane thing to do and you can not expect a sick or injured partner to work well.
Be in tune to what is normal for your dog and be observant. If your dog is off its feed, it develops a cough, it's drinking copious amounts of water, it's stools are not normal in appearance and/or smell, if suddenly a limp appears, or the dog is constantly scratching--check it out. If you find nothing wrong but the symptoms continue, get your dog to the veterinarian.
Be sure you keep your dog on preventative medication for fleas/ticks and heart worm, up-to-date in routine inoculations, and have annual physical and dental work ups. Periodically check your dog for foreign materials that might have lodged in-between the pads of the paws, ears, eyes. Feel for any bumps, swellings, cuts, etc. Physically know what your dog looks like, smells like, and how it normally moves. Take note of your dog's moods. Your dog should not be lethargic, dejected, despondent, or anxious, jittery, etc. Know your dog so that if anything goes from routine/normal to out-of-the-ordinary/strange you will detect it quickly and able to address potential issues. On the other hand, do not be over anxious or zealous in keeping your dog in tip top shape. Neither extreme is good.
Take care of your partner and he/she will take care of you and your patient.
Most breeds of dogs have a special trait that is a characteristic of their breed. For example: huskies love to forge ahead--to pull. Man has used that skill to his advantage. But that particular trait is not desired in an Alzheimer's dog because it is not needed to complete the work task. On the other hand, herding dogs are prized for their skill in herding/retrieving. It is critical that the Alzheimer's dog "retrieve" the caregiver to the location of the patient. In selecting a canine candidate for Alzheimer's training it would be feasible to choose the herding dog over the husky.
You need to know exactly what the Alzheimer's dog has to do to successfully perform its job. Then you will recognize what canine traits are necessary for the dog to learn. Alzheimer's dog will have to listen for its special sound, identify it, verify that the patient is indeed up, alert the caregiver that the patient is on the move, and then retrieve the caregiver to the patient's location......... listening and retrieving skills are top priority. The dog must naturally use its ears more than its nose. You do not need a dog that is always "following its nose for scent", but rather the canine that is sharp and focused upon sounds. Key to Alzheimer's dog is using its ears to hear if the patient is getting up and then retrieving the caregiver to the patient's location.
Bad habits are not acceptable in a dog that you are relying upon to be your partner. Catch the negative behavior early and replace with a good habit. This means you must be ever vigilant. You expect your children to have good manners, likewise for your dog. You do not have the time nor money to be constantly cleaning up canine messes or worse replacing items that the dog has destroyed. Bad manners are not conducive to promoting a healthy human/animal partnership. Being ashamed of your canine's bad behavior is not going to help you, or others, to want to have your dog around. Conversely, a dog that understands and is contented to obey your rules is the dog that you will be happy to have by your side. Remember your dog craves your love so be sure to let it know when it has pleased you.
Don't let negative habits develop in the first place. I'm not advocating that you aggressively thrash your dog but let it know when its behavior is not acceptable. You must be observant and consistent in reinforcing your expectations. If you allow your "cute little dogie" to get away with things then it will become a monster and its your fault. In a humane manner let your dog know what you will allow and be prepared to reinforce your rules. The better manners and obedience your dog has, the better it will perform its work task. There is a definite correlation. So keep your dog focused and sharp in manners and it will willingly give you its best work performance.
You have trained your Alzheimer's assistance dog to take its sound-awareness job seriously. It knows that it must be on duty 24/7. Non-neutered males certainly have only one thing on their minds when a bitch is in season and within smelling distance. There is no way that he is going to give his sound work job top priority over (dare I say it?) sex. A female in season will also be distracted from her work. Sex again. Once she has her pups "motherhood" will be her biggest concern. You can not expect your dog, either male or female, to not be diverted by Mother Nature. Sound awareness will come in second place every time. Neither you nor your dog need this major, repeated distraction. The best thing you can do is eliminate it entirely. Have your dog spayed/neutered. Now, you can expect your dog to target its sound at all times. It does not matter if the dog is eating, sleeping, playing, investigating whatevers, it should always be listening for its special sound. And, by the way, your dog is expecting you to play your role every time it alerts you, without exception. Together, no matter what each of you may be doing, you need to successfully fullfill your respective parts. You are a team.