Katharine McPhee's Very Special Rescue Dog Wilma Dies

Katharine McPhee is saying goodbye to a very special friend ... one she adopted late in life to show her love and happiness in her remaining few years.

We're talking about Wilma ... the rescue dog Katharine took in a few years back. What makes this special is that Wilma was 12, so Katharine knew she would not have the dog for very long, but she wanted her to enjoy her sunset years.

Katharine posted her tribute Monday night ... "Here's a little tribute to my girl Wilma… also known as Willy… ”

She went on ... "Wherever she went her tongue was hanging out without fail." "She traveled the world with me. Was at every rehearsal for my first Broadway show… Thank you Willy for all the great years."

Katharine's gotta be struggling with this, but she clearly gave the best life to Wilma that she possibly could. Great job, Ms. McPhee.