Lisa Hulber didn’t think twice when the results of her mammogram came back negative for breast cancer. After all, her doctors hadn’t detected the presence of any tumors.

But Hulber’s dog, a rescued Hound mix named Effie, disagreed with the doctors.

It seems Effie could sense that something was wrong; she sniffed her owner to the point that Hulber decided to seek another opinion, and on that second doctor’s visit, Hulber found out that she did indeed have breast cancer.

The doctors performed an excisional biopsy to remove the tumor, and when Hulber went home to recover, Effie’s diagnostic sniffer was at it again.

“Effie was right, twice,” Hulber said. “She found the original tumor and after they did the excisional biopsy she found the only lymph node that it was on.”

Since Effie’s diagnosis, Hulber underwent a double mastectomy and a 20-week round of chemotherapy. She will begin radiation treatments soon.

“It’s hard to go through cancer and stuff like that,” says Hulber of her ordeal, but she will forever be grateful to Effie for giving her a chance to fight the disease. “I’m not a ‘woe is me’ kind of person and knowing what she did for me, that gift, that’s what makes me cry.”

Hulber says that this is not the first time that Effie has detected the presence of cancer; Effie was the first to know when the family’s kitten came down with the disease.

Hulber first rescued Effie as a volunteer for Last Day Dog Rescue in Livonia, Michigan. Hulber, a foster parent for the organization, fostered Effie and her seven puppies.

After finding forever homes for the pups she decided to adopt Effie, and it turned out to be a lifesaving decision for them both.