Katy Perry has divided fans and sparked a mass online debate after revealing she has put her pet dog Nugget on a vegan diet.

The Cry About It Later songstress took to Twitter on Saturday evening to explain she and the pooch have been on a "vegan journey" since September.

Katy tweeted to her 109 million followers: "I’m about 95% ready to be 100% VEGAN... my dog Nugget has been joining me on this journey for the past 4 monthz. Pray for us ok. [sic]"

The revelation has been praised by some but also led to accusations that Katy is forcing the lifestyle on her pet who can't decide for himself.

Katy Perry is feeding her dog a vegan diet

Within minutes the post was flooded with thousands of replies.

Hitting out one fan raged: "Dogs can’t go vegan they’re carnivores."

Another added: "Katy I love you but forcing your dog to be vegan is abuse I don’t care what anyone says.

"A dog can’t make a choice so your forcing him/her to be vegan when dogs are meant to eat meat.

Some fans argued Katy was forcing her beliefs on her dog who can't consent

"Try putting meat and vegetables in front of your dog and see what it picks."

A third continued: "If you talk to any vet, they will recommend feeding your dog meat and veggies.

"They get vital nutrients from meat. Don't force a diet on your dog just because it's your diet."

A fourth hit out: "No. Forcing your beliefs and diets on your pets who are not meant to be vegan is not okay.

Katy says she is almost ready to be fully vegan after trying for four months

"While dogs can survive on a vegan diet, it’s not what’s natural or appropriate for their species.

"Dogs are omnivores at most, don’t force them to be vegan just because you are; it’s cruel."

However, others welcomed the news, including animal rights activists Peta.

Peta said: "Wonderful news! We’re SO happy for you—and for Nugget, too. You’ll both love how it feels eating clean and helping animals."

Agreeing another of Katy's supporters argued dogs can thrive by living on a meat-free diet.

They wrote: "Dogs are omnivores and in fact rive on a plant based diet - believe it or not.

"The longest living dogs are also all vegan. Nugget will be much, much healthier this way so good on you Katy."