Amanda Owen says her family is in mourning after finding farm dog Kate had died in her sleep.
The Yorkshire Shepherdhess said she went to wake her trusted pet and sheep dog, only to find she had passed away in her kennel.
Owen, 48, paid tribute on Instagram, saying: "Then there’s the other kind of mourning.
"Where you go to get your faithful workmate, companion, colleague & friend from her kennel. Only to find that she has passed away in her sleep.
Ben Fogle, who has worked with the family when the farm featured in his show New Lives In The Wild, commented : "Oh no. I’m so sorry."
Owen lives on Ravenseat Farm with her family, estranged husband Clive and several working farm dogs.
Beyond The Yorkshire Farm: Reuben & Clive — launching on Tuesday, 6 December — will focus on farmer Clive and eldest son Reuben's first year in business on the farm.
Yorkshire Shepherdess Amanda, 48, confirmed her separation from 67-year-old farmer Clive earlier this year after 21 years of marriage.
The couple had previously denied rumours their relationship was under strain.
She said in a statement: "Clive and I are sad to confirm that we have made the difficult decision to separate.
"This hasn't been easy, but we both believe it's the right choice for the future of our family.
"Although we are no longer a couple, we continue to work on the farm and co-parent together, with our number one priority the happiness and well-being of our children."
The couple have nine children together: Raven, 21, Reuben, 18, Miles, 15, Edith, 13, Violet, 11, Sidney, 10, Annas, eight, Clemmie, six, and Nancy, five.
The Yorkshire family rose to fame in 2011, after their 2,000-acre working farm featured in The Dales with Adrian Edmondson.
They have since made guest appearances on This Morning, and have starred in their own Channel 5 reality show Our Yorkshire Farm since 2018.
Amanda and Clive met in 1995, when she was 21 and he was 42. Clive's first wife – of 13 years – had recently left him and Amanda went to work on his farm as a shepherdess.
Watch: Amanda Owen leads procession of sheep over Southwark Bridge