I have two chihuahuas that are six and ten. I’ve raised them from puppies to now. They are well mannered, but very spoilt as well. Before then I had dogs till they were 15 and 18 so I know how to take care of elderly dogs, too. While I’ve always had small dogs, I adore big dogs as well and volunteered at a rescue that mostly saved big dogs. While at the rescue, five to eight dogs would come out of their kennels at once to be played with and loved on. I have no problem picking up waste, giving medicine to, or giving baths/grooming dogs either. My dogs are on a great schedule as far as feedings and going potty so the dogs I’d care for would be on that schedule as well.