Vegetarian and Vegan Diets Factsheet

It is important to distinguish manufactured products and home- made diets. Formulating complete (where the food contains all the nutrients that an animal needs) and nutritionally appropriate pet foods is challenging, particularly for species such as the cat. UK Pet Food advises not to feed home-made diets to dogs and cats as these may risk nutritional deficiencies and imbalances which can have serious health consequences. This advice includes home- made vegetarian or vegan diets.

In this factsheet we expand more on manufactured vegetarian and vegan products.

Manufactured vegetarian and vegan (entirely plant-based) diets are now available for both cats and dogs. With advancing technology and research, nutrients that were previously only available from animal-based ingredients can now be made synthetically or be sourced from novel ingredients.

Whilst it is technically possible to make complete and balanced vegetarian and vegan diets for dogs and cats, these require careful formulation by highly qualified animal nutritionists to ensure that they meet the needs of pets at their various life stages, as well as addressing the particular needs of the species concerned.

It is important to ensure that any diet fed to a pet contains all the nutrients that they need, in the correct amounts and proportions, and of a quality that the animal can digest, absorb and metabolise. A reputable manufacturer, where diets are formulated by qualified and experienced animal nutritionists and/or veterinary nutritionists, would be a good starting point if considering a diet change.

Conventional dog and cat foods, which include animal-based ingredients, have been fed to generations of pets for decades and the pet food industry has a comprehensive understanding of the nutritional science behind these products, helped by the very large number of animals fed in this way. Some manufacturers will also carry out feeding trials – where the food is fed exclusively to a number of pets for a suitable length of time and the pets’ health is evaluated – and this helps to ensure a food’s adequacy.

Vegetarian and vegan diets are relatively new to the market and potentially fed to a relatively small portion of the pet population. For this reason, extensive data are not yet available to study the effects of these type of diets on long-term health of dogs and cats. However, to date, there is little evidence of adverse effects arising in dogs and cats on vegan diets.¹ In the growing body of published research investigating outcomes in pets fed vegetarian or vegan foods, the notable observation to date is that these foods (as for all foods fed to pets) should be appropriately designed and be nutritionally sound.

Dogs are omnivorous carnivores which means that they can digest and utilise both animal- and plant-based ingredients. Their physiology can adapt to a well-balanced and carefully formulated vegetarian or vegan diet, given their individual circumstances. There is a wide range of commercially prepared ‘complete’ vegetarian, and some vegan dog foods available on the market from which pet owners can choose.

Cats are obligate carnivores which means they cannot obtain all the nutrients that they need from the plant kingdom but they can digest and absorb some nutrients from plant based materials. Cats have highly exacting nutritional needs, such as high requirements for protein and amino acids. For this reason, we advise owners to think very carefully before providing a vegetarian or vegan diet for their cats. There are a number of vegetarian and vegan diets available on the market and manufacturers should be willing to provide sufficient information to reassure you that their product is complete and balanced and meets all the nutritional needs of your cat. It is also important to discuss this option with your vet in the context of your cat’s individual needs and source any product from reputable manufacturers only.