They rely on taurine, vitamin A and arachidonic acid found in meat

The focus on cats is because they are technically carnivores and need meat

Pet owners who force their cats into being vegans could risk seriously damaging their health, the RSPCA has warned.

Owners concerned with ethics are turning to veganism and vegetarianism and bringing their cats with them.

Pet food suppliers are now following suit, with one in six now branching out into vegan and vegetarian food stuffs for animals.

But a plant-based diet is not sufficient for a cat as they need taurine, vitamin A and arachidonic acid found in meat, warned the charity.

Cats are technically carnivores, unlike dogs who can survive withoutmeat

Harry Bolman faced hostile backlash after placing his cat Uma on a strict vegan diet last year

The focus on cats is because they are technically carnivores and need meat as opposed to dogs who can theoretically survive on plants alone.

A spokesman for the RSPCA said: `Under the Animal Welfare Act the law requires an owner to ensure all the pet's needs are met. This includes a healthy diet, as well as suitable living conditions and protection from pain, suffering, injury and disease.'

'Cats are strict carnivores and depend on some very specific nutrients that are found in meat including taurine, vitamin A and arachidonic acid so can become seriously ill if they are fed a vegetarian or vegan diet.

'If an owner is considering switching their pet's diet they should consult with their vet to make sure that it will meet all their pets nutritional needs which will depend on many factors such as age, health and lifestyle,' they added.

Experts agree that it is even a possible welfare issue and warnings came after the National Pet Show in Birmingham this month displayed non-meat options to potential buyers.

Pet shops have reported the growing demand for grain and gluten free options for their pets.

RSPCA has warned of tough sanctions for pet owners who neglect their pets' health

An expert from Benovo, a company that has been making 'ethical pet food' since 2005, told The Daily Telegraph the apparent health issues the RSPCA were talking about are all hogwash and that any vets that disagreed with him were struggling with 'an unshakable ideology'.

A 53-year-old called Harry Bolman also thinks plant-based food is the 'healthiest diet' for felines.

He feeds his cat Uma, five, a diet of vegetables and special vegan cat food and claims she's never been healthier.

Harry - from Australia - who has been vegan for the last 38 years, said despite negative comments from people who he claims say he is 'abusing' and 'killing' his cat, he stands firm in his position.

Uma, 5, is on a diet of vegetables and special vegan cat food and 'has never been healthier'

'Uma is very healthy. She's got the whitest coat, a great appetite and is full of vitality. Regular processed cat food is abysmal. It's just bits and pieces of different animals which is absolutely revolting. There is no way I'd feed my cat that. I don't support meat-based pet food, it goes against my ethics altogether,' Harry said.

According to the RSPCA, cats 'need a source of animal protein to survive' – and while all mammals need the nine essential amino acids, cats are unique as they require taurine and arginine in their diets – which is only found naturally in meat.

It is added to the likes of Benovo's foods but veterinarians still say that it's inappropriate because it's based on very limited and/or poor research.