The princess of Wales' brother, James Middleton, is "just about holding it together" as he grieves the loss of his beloved dog, Ella.
The 15-year-old Cocker Spaniel was the first dog James ever owned and he said he would "miss her terribly".
Sharing the sad news in a post on his Instagram account, James paid tribute to his "dear Ella".
He wrote: "It is with great sadness that I announce my dear Ella has passed away
"For 15 years Ella has been at my side, from my darkest days to my happiest. I’m going to miss her terribly
"Ella had a very short illness, she slipped away in my arms at home and is now buried in the garden alongside Tilly. I took this picture just a few hours before she died."
He added: "I’m just about holding it together to write this, and despite the fact I knew this day was coming, it doesn’t make it any easier
"Goodnight my darling Ella, Alizee and the dogs will take good care of me."
Ella helped James through his struggles with mental health and inspired him to start his own brand of natural dog food, named after her.
Describing the story behind Ella&Co on the company website, James said: "A few years back, my dogs helped pull me out of a really difficult battle with depression.
"When I reached the other side, I set out on a mission to make their lives just as happy and as healthy as they’ve made mine, starting with the food they eat."
He said that Ella has had a "huge influence" on his adult life.
James added: "Ella is the first dog I ever owned by myself and she has had a huge influence on my adult life.
"It is largely because of her that I was able to overcome my struggles with mental health and I have since had her registered as a therapy dog, she can provide that same support to others.
"As a mother and grandmother, she is both the matriarch of our pack and the inspiration for Ella & Co."
Ella was the matriarch of James' pack of beloved dogs, which includes four more Cocker Spaniels as well as a Golden Retriever who welcomed eight puppies in the summer.
