United Kingdom, Feb. 11 -- Vanessa Hudgens is heartbroken after her dog Darla had to be put down.

The 37-year-old actress has posted an emotional tribute to her beloved furry friend - who she described as "the smart little lady" - as she revealed the poor pooch's body had been "failing her".

Alongside a carousel of pictures, Vanessa wrote: "Anyone that knows me knew Darla.

"She went everywhere with me. Traveled the world. Was there for me every single step of the way.

"She was the smartest little lady I've ever known. I couldn't have asked for a better dog. I am beyond heart broken today.

"Putting her down was one of the hardest things I've ever had to do, but her little body was failing her and it was her time.

"I already miss the ...