has spoken about how the bond between him and his dog played an essential role in his journey to stardom.

The Hollywood legend recently took to Instagram to reminisce about his beloved Bull Mastiff, Butkus. He credited the pooch with helping him write the 1976 classic , which was the film that launched his career.

Stallone revealed that he was once so financially destitute that he had to sell Butkus for just $40 to make ends meet.

Alongside a vintage photo of himself holding the puppy, he wrote: "1971... Since we're on the subject of 'man's best friend' this is myself and Butkus as a puppy, we were both thin, hungry and living in a flophouse above a subway stop. I used to say this apartment had '... Hot and cold running roaches.'

"Anyway, there was not much to do except spend time with each other and that's where I started to learn the craft of screenwriting. Since I never went out, I relied on his companionship. And actually, it was his idea to write Rocky, but don't tell anyone..."

Despite his deep love for his canine companion, Stallone was forced to make the heartbreaking decision to sell him. He explained: "Years later when things got even worse I had to sell him for $40 in front of a 7-Eleven store, because I couldn't afford food."

Fortunately, after Rocky became a massive success, Stallone was able to reunite with Butkus - for a hefty price.

He shared: "Then like a modern-day miracle, the screenplay for Rocky sold, and I could buy him back, but the new owner knew I was desperate and charged me $15,000 ... He was worth every penny!"

The actor expressed his gratitude to his loyal companion, calling Butkus his "best friend" and "confidant" during his toughest years.

Fans flocked to Instagram to praise Stallone's story, with one user writing: "What a story. You're a great man for buying him back. I couldn't sell my dog though, I'd rather starve."

Another added: "This is a demonstration that you are a man of honour..." while a third commented: "What a beautiful story!"

Sadly Buktus has now passed away. Stallone paid tribute to him in an emotional Instagram post, saying: "I TRULY feel for people that have lost their great beloved Pets... ! Tragically, It is a loss that never fully fades... So Everyday you must cherish their REAL love while it is here , Because once it's gone it's never quite the same .. Keep Punching Pet lovers."

After his brush with poverty the actor went on to build one of the most illustrious careers in His family also went on to join the entertainment industry.

His son Seargeoh followed in his footsteps, while daughters Scarlet, 22, Sistine, 26, and Sophia, 28, also pursued careers in acting. However, the star suffered a tragic loss when his eldest son, Sage, in 2012 due to atherosclerosis, which led to a heart attack.