Vegan pet owners feeding their animals meat-free diets are putting their animals' health at risk.

Dogs and cats are carnivorous animals that require meat in their diet and removing it can have fatal consequences, a veterinarian has warned.

'When these are depleted over time there are many negative health impacts,' managing vet at RSPCA NSW Sydney Veterinary Hospital Dr Chris Greenwell told the Daily Telegraph.

'If you're denying proper care to a cat you're effectively breaching your own theoretical values with dietary choices.'

Health risks for cats who eat a vegan friendly diet can be fatal (stock photo)

Cats and dogs both have small guts that can quickly and effectively break down meat products, while plant-based options can be a lot harder for them to digest.

Cats get an amino acid called taurine from eating meat which is essential to their diet. They also get arginine, arachidonic acid and A and B vitamins.

Removing these components from a cats system can cause severe problems including heart failure, birth defects and liver problems.

Dogs are better equipped to handle a plant-based diet, but still require foods rich in protein and can suffer from heart diseases and vitamin D and B deficiencies from avoiding their natural food source.

Pets require a balanced diet to gain their natural nutrients and benefits from their food, regardless of personal choice.

Supplements are available for pets with vegan diets, and can be taken in a number of different formulas for different animals.