Saying goodbye to a dog who has lived a long, full life can be the sweetest sorrow.

But saying goodbye to a dog who has lived a long, unhappy life can be almost too much sorrow.

That’s Lisa Letson’s sad specialty – her rescue, True & Faithful Pet Rescue Mission, focuses on old, sick and disabled animals.

They escape an anonymous end at kill shelters and live their precious few last days in love.

Take Lester, for instance, a dog featured on The Dodo last week. The 9-year-old Akita mix, who suffered from a litany of health issues, was ebbing away his twilight days at Miami-Dade Animal Services when Letson found him.

Miami-Dade Animal Services

She took Lester out of there. He died just two days later.

“At least he didn’t die alone,” Letson tells The Dodo.

Lisa Letson

And now, there’s Lilly.

As with every dog Letson rescues, she’s hoping this tiny papillon will buck the odds and live long enough to catch up on all the love she missed.

When she was first found on the streets of Miami, it didn’t look promising. Much of her body was covered in growths. Her mouth was completely rotten.

Did we mention that, at 16, she’s as senior as a dog can get?

Animal control responded to a call about the wandering dog. They used a long steel pole to catch her. And soon, she was in an even steelier embrace – as a senior dog at a kill shelter.

Miami-Dade Animal Services

By most accounts, she was virtually unadoptable.

Only Lilly didn’t spend a night at Miami-Dade. Letson picked her up immediately. Today marks Lilly’s 17th day in the hospital, where she has been undergoing a battery of operations.

Lisa Letson

Her mouth is a mess. And those growths seemed everywhere – including her tail, which is scheduled to be removed completely.

But her heart shows every sign of remaining intact. Even bursting with love.

Lisa Letson

“I want to get her adopted,” Letson says. “Seniors deserve the pot of gold at the end of the rainbow. They make every moment count.”

Lisa Letson

Who would have ever guessed the twilight of a sick, abandoned dog could be so … bright?

Lisa Letson

Rescuing old and ailing dogs is heartbreaking. It can also be bank-breaking for a small nonprofit like True & Faithful. The bill for Lester, who spent only two days at the rescue, was nearly $1,200.

And Lilly? Those bills have only begun to be tallied.