Jane Fonda "cried every night" when her dog was going through chemotherapy.
The 77-year-old actress got the treatment for her pet pooch Spencer after he got cancer, but the Hollywood star insists she would never inflict chemo on a pet again after watching her Golden Retriever go through the "ordeal".
She said: "Spencer lived for 13 years. He died of cancer. I adored him so much that I put him through chemotherapy, something I would never do again, no matter what.
"You can't explain to a dog that it's for his own good.
"I was married to Ted Turner by then and we were on one of his ranches in New Mexico.
"The vet was an hour away so I moved in and slept with Spencer in his little cage at the hospital while he went through the chemo ordeal. I cried every night."
When she passes away, the 'Gracie and Frankie' star would like her ashes to be scattered in the same place as Spencer's.
She said: "I had Spencer cremated and we sprinkled his ashes on what was once a Native American vision quest sight where I sometimes went to meditate. Ted and I had decided we would be put there as well when we died."
After Spencer, Jane had another Golden Retriever, Roxy, who also died, before getting Tulea, a Coton de Tulear breed of dog who she still has today.
And just like with Spencer and Roxy, Jane can't bear to be away from her four-legged friend, and even finds it harder to sleep when she is not with her canine pal.
In a post on her website, she wrote: "She goes just about everywhere with me and when I am without her I ache for her. It's a physical thing. I feel a pang in my body and it's harder to sleep. She follows me like a shadow and is so smart."