Before medical tests provided confirmation, actress Shannen Doherty said her dog was the first to detect her breast cancer.

In an ET exclusive interview, Doherty said her dog Bowie would "obsessively sniff" on the right side of her body, where her cancer was eventually diagnosed.

Doherty, 45, was diagnosed with breast cancer in 2015, and revealed this week that the cancer has spread to her lymph nodes.

Doherty said Bowie is even more protective of her than before the diagnosis.

Bowie is named after the late music legend David Bowie.