Jennifer Aniston, Lily Collins and Tracee Ellis Ross among stars to send support message to Jennifer Garner following dog's death

'The Morning Show' actress Jennifer wrote: "Oh Jen ... I'm so sorry. Sending so much love."

'Emily in Paris' star Lily also sent her sympathies, as she posted: "Oh I'm so so sorry. Sending you the most love and light and hugs."

Tracee shared a string of pawprint and heart emojis and wrote:" These furry beings bring so much goodness."

Rachel Zegler simply posted: "oh birdie. we love you.(sic)"

Kristen Chenoweth also expressed her love of the dog.

She wrote: "I loved birdie [pawprint emoji] she was a cutie. You will see her again!![rainbow emoji] (sic)"

In her post announcing the news, the former 'Alias' star had questioned if it was "nuts" to mourn a pet amid the current state of the world, but Holly Robinson Peete insisted it wasn't "wrong" to be devastated.

The 60-year-old actress wrote: "It's just the hardest worst pain. No it does not seem wrong to mourn our animals. They're there for us no matter what!

"Rest in peace sweet Birdie."

Jennifer - who has Violet, 18, Seraphina, 15, and 12-year-old Samuel with ex-husband Ben Affleck - had admitted she was stunned to learn just how ill Birdie was when she suddenly went off her food.

Sharing a series of photos of her pet, she wrote: "It is hard to know how to write this - it seems nuts, given the world, to mourn a pet, but since we have shared Birdie with all of you, it only seems fair to let you know of her passing.

"Birdie let us know on Thursday that she wasn't feeling herself (a renowned foodie, Birdie never missed a meal).

"We were surprised to learn that, not only was she very ill, she was at the end of her life."

Jennifer felt Birdie clung on to life for a few more days so Violet could return home from college to say goodbye.

She added: "The vet told us that dogs often hang on until their person comes home from college and we believe Birdie did just that, so that we could pet her soft ears together and thank her for being the world's best dog.

"Birdie loved to be read to, always found her way into a Pretend Cooking Show, and knew just how to give people what they needed (as evidenced by her happy days as a dog therapy team with Mo).

"She lived a happy dog life and is now in the role she was born to play: angel girl.

"It's a gift to love and be loved by such a creature as Birdie the Doggie."