For more than 30 years, Sher Polvinale and her husband, Joe, took in as many unwanted dogs and cats as they could rescue and devoted their lives to finding them loving new homes. 
Then, as the Polvinales grew older and their pace became a bit slower, they noticed something: Many of the dogs and cats they took in from shelters and the streets were older too, and harder to place in energetic homes with young families. So in 2006, they came up with a plan. They would turn their Gaithersburg, Maryland, home into a non-profit retirement home, where older pets could live out their twilight years in dignity and comfort. 
Eleven years later, Sher, 69, now runs House With a Heart with help from a loyal group of volunteers, since Joe died of lung cancer in 2008.
“I miss him every day, but I know he’d be proud that we’re still taking in as …