Zac Efron has saved a dog from euthanasia.

The 'Greatest Showman' actor has adopted new furry friend, Maca, and has been teaching his canine companion to sit and listen to his commands.

He shared a photo of himself and the dog on Instagram and wrote: ''Hey planet, this is MACA. #adoptdontshop (sic)''

He also shared footage of himself and his new pet on his Instagram Story.

The 30-year-old star adopted Maca from the the Bark 'n' Bitches pet shop in Los Angeles, who ''stepped in'' before the pooch was due to be taken to the ''kill room''.

The store revealed on Instagram: ''Tilly now MACA was being led to the kill room when we stepped in and said we would take her.

''She was turned around and brought to us! This guy named Zac Efron came in (we hear he is an actor, but we think he actually waits tables) came in and fell in love.(sic)''

And though Zac had only meant to care for dog for a short time, he couldn't resist offering a permanent home to the animal.

They added: ''He went through our application process and fostered MACA and just could not give her back. So MACA now lives with Zac! This is her happily ever after! Happy life MACA! Happy Life.(sic)''

The 'Baywatch' star was previously left devastated when his ''best friend'', Puppy Efron, passed away in August 2016.

He wrote on Instagram at the time alongside a picture of himself and the dog: ''Through thick and thin you've always been my best friend. I'll see you at the finish line, RIP Puppy Efron.''