Veganism has been dubbed the fastest growing lifestyle movement in the UK, with the practicing population increasing in the UK by 350% over the past ten years. Involving the removal of all animal products and by-products from one’s diet alongside the conscious removal of all animal exploitation from one’s lifestyle (such as ceasing wearing leather and using non animal-tested products), most vegans list ethical and moral concerns as the main motivators behind their switch.  For some vegans, the drive to prevent animal slaughter is so passionate that they wish to extend their meat-free ways to the diet of their pets. This is of little issue when considering rabbits and many rodents whose diets are largely composed of plant-based carbohydrates. However, when considering popular companion pets such as cats and dogs, a serious debate entails. Whilst the ever-controversial organisation PETA claims that ‘the nutritional needs of many dogs and cats can easily be met with a balanced vegan diet and certain supplements’; there is a large amount of evidence suggesting that feeding such animals meat-free diets can have catastrophic effects on their health.

According to Professor Joe Bartges from the University of Georgia College of Veterinary Medicine, cats are obligate carnivores- meaning they can only gain the nutrients they need to survive through the consumption of meat. Taurine, an amino acid essential to the metabolism of dietary fats, is only found in animal sources. Most mammals can synthesise taurine for themselves from other amino acids. However, this is not true for cats, who are unable to make taurine for themselves so rely solely on dietary sources. If cats do not receive sufficient levels of taurine in their diets they can suffer with retinal degeneration, dilated cardiomyopathy (enlarged heart valves) and reproductive issues. This therefore results in a large problem when feeding cats vegan food, due to the only sources of taurine being animal in origin. Worse still, cats lack the enzyme needed to produce another amino acid found in meat named arginine – essential to the removal of toxic ammonia from the body. Whilst there are some plant sources of arginine such as oats and nuts, these foods are only recommended to be fed to cats in small quantities so are unlikely to provide enough arginine to preserve a cat’s health. If dietary arginine levels fall, cats can experience vomiting, weight loss, neurological issues and even death. Bartges also warns of hearing loss, sight loss and heart problems if cats do not consume enough vitamin A, vitamin B12 and arachidonic acid- all of which are challenging to consume with the elimination of all animal products. Cats lack the enzyme needed to break down carotene (plant originating vitamin A), leaving them reliant on animal sources or risk going blind. In a final swoop against feline veganism, eating a plant-based diet leaves cats vulnerable to Feline Lower Urinary Tract Disease (FLUTD): a precursor to urinary stones that results from high urine pH levels- caused directly by a vegan diet. If left untreated, FLUTD can result in pain and can even be life-threatening. 

Whilst it is clear that the consumption of a vegan diet is a serious health threat to cats, the debate is a little greyer when it comes to dogs. Bramble, the 2002 Guinness Book of World Records holder for ‘oldest dog’ who lived to the grand age of 27, is frequently used to promote canine veganism after reportedly living on lentils and vegetables. Unlike cats, dogs are omnivores and possess a digestive system capable of deriving and digesting nutrients from plant sources. However, this does not mean providing a nutritionally complete vegan diet for your dog is easy. Dogs have a significantly higher protein requirement than humans, which is challenging to fulfil consuming plants alone. Whilst higher protein foods such as lentils, beans and soy are suitable for dogs, they are all Low Biological Value protein sources. This unfortunately means that you need to eat far more of them to consume the same amount of protein found in High Biological Value sources such as meat, which may be difficult for dogs. Further, dogs also risk deficiencies in vitamin B12 (found mostly in animal products and essential to the nervous system), calcium, iron and taurine which can all lead to nasty health complaints, some as extreme as heart failure.

Whilst there is no doubt adopting a vegan lifestyle has its benefits for humans (removing animal products from your diet could reduce your carbon footprint by up to 73%), trying to veganise our best loved pets is a miCnefield. Whilst it is possible for dogs to follow a healthy vegan diet (if under close supervision from a vet), the reality is that most owners will unlikely have the knowledge, money nor patience to provide nutritionally complete meals as this will require supplementation to ensure protein intake is sufficiently high. When it comes to cats however, the conclusion that a vegan diet will cause serious or fatal harm is clear- despite the many claims otherwise online. In order to ensure vegans harm no animals including their own, it is best advised for those opposed to buying meat in any circumstance to house degus, chinchillas and rabbits as these animals are natural herbivores.