I was thinking of prefessional nursing ... people who have a career of care giving and familiarity with such scenarios
Also, judging from the pictures that I saw yesterday afternoon, there would have been an additional factor against calling in outsiders. Over the years, Hackman and his wife had tastefully renovated the original home and added a guest house and other outbuildings.
For some time though, the interior of the home had become an embarrassing mess. There were accumulations of unwashed clothes, dirty dishes, trash cans with used diapers, counters with an excess of personal care items, household debris, and a pantry full of expired food. Rats were evident on the outside of the property.
Apparently, as Gene Hackman's Alzheimer's Disease progressed, he and the household dogs required constant care and attention from his wife. That let routine house chores accumulate to the point of squalor. The Hackmans may have feared that help from outsiders might trigger adverse reports to the authorities and legal intervention to remove Hackman from the home.