Nine years ago, Nicole Siekert drove from Wisconsin to Illinois to adopt a young mixed-breed dog who needed a home. She had a feeling that Abby was special. What she didn’t know was that one day, this amazing rescue dog would save her life.

“There was just something about her, and I knew she was meant for us — I just knew it,” says Siekert, who spotted a listing for Abby while searching online for adoptable Collies and Aussies.

“She was the first one that popped up,” she explains, while remembering being transfixed by Abby’s beautiful eyes. “They’re just so soft and so welcoming, and it was like she was just looking right at me. I immediately told my husband we had to go to Illinois.”

The couple packed up their other dog, a rescued Sheltie-Aussie mix named Shelby, and headed to Finally Home Holistic Recovery and Adoption in South Elgin, Illinois, to meet Abby. According to Siekert, staff at the rescue said this malnourished stray pup was one of the smartest dogs they’d ever encountered. The intelligence behind Abby’s stunning eyes hooked Siekert right away.

“The second I saw her, I fell in love with her,” she recalls. “It was almost like we had found our long-lost family member. It was pretty awesome. I’ll never forget that moment when we first saw her.”

It turned out Shelby was just as excited as Siekert was. The older dog was full of excitement as she greeted Abby and immediately engaged her new sister in play. It was obvious to everyone that Siekert was right — Abby had found her family.

Four years later, the Siekerts added two more family members to the pack when their twin girls were born. Abby was no longer the baby of the family, but she didn’t mind. As the twins grew older Abby relished the attention they would give her, proudly partaking in games of dress-up and nudging their little hands for extra petting. Having the twins as playmates was especially helpful for Abby after her original play partner, Shelby, died unexpectedly this past summer.

“She was 10 years old,” Siekert explains. “Apparently there was a mass in her spleen that just burst. It was pretty awful how everything happened, but it all happened within a two-hour timeframe.”

Before she died, Shelby got sick in Abby’s favorite spot behind the recliner. For days afterward, Abby would stare into the empty space, but didn’t dare take a nap there.

“She just looked so sad. I think she had a broken heart,” says Siekert, who watched as Abby started taking over some of Shelby’s responsibilities.

“I’m a Type 1 diabetic, and Shelby basically would always know if I was getting sick before I did,” she explains, adding that Shelby would act super clingy when she sensed a blood sugar issue.

“Now Abby has completely taken over that role — completely. It’s almost like a little bit of Shelby is with her now.”

After a recent shoulder surgery Siekert, wound up getting an infection — a very dangerous situation for a diabetic. When Abby started following her around (even into the bathroom), Siekert knew something was wrong. Eventually, her husband ended up calling 911 as she went into ketoacidosis ( a serious condition that can lead to a diabetic coma). Abby was so concerned, she tried to follow the paramedics while they carried Siekert out of the house on a stretcher. Family members had to hold the worried dog back.

With that kind of track record, it’s no surprise what Abby did next. One Thursday morning in February, Siekert woke up feeling ill. Her young daughters also seemed out of sorts, but neither of the twins had a fever and they both wanted to go to school.

“I got them on the bus right outside, and then came back in and could hardly stand up anymore,” Siekert says. “That’s when I tried to lay down, and Abby would not let me.”

“She was just lifting up my head with her nose. She was literally up on my pillow, and every time I tried to remove her — because I just felt so sick and all I wanted to do was sleep — she would come closer.”

Assuming Abby needed a bathroom break, Seikert tried to let the dog out, but instead of going outside Abby rushed down to the basement and wouldn’t come back when called. Seikert went down after her and had a startling realization.

“That’s when I started hearing the chirping. She was sitting next to the CO detector, and it was alarming. That’s when it all clicked, I’m like ‘oh my gosh baby — I get it! I get it’”

The Seikerts had been having trouble with thier furnace, but didn’t know it was allowing carbon monoxide to build up in their home. They couldn’t sense the danger, but Abby could.

“I would have just fallen asleep, and the doctor said I wouldn’t have woken up,” Siekert says. She’s grateful to Abby for keeping her awake and says her amazing dog proves that former strays can be just as smart, loyal, and loving than their pedigreed counterparts.

“They say we’re rescuing them, but they are truly and literally rescuing us. It’s amazing.”