There are many of us who choose to eat plant based diets by becoming either a vegetarian or vegan. The question is, can the same choice be made for our pets?
Pet nutrition is a complex science relying on an optimal selection of high quality ingredients and precisely balanced nutrients allowing for a pet’s age, lifestyle, current weight, and medical history. It is possible that at some point during their lives, certain pets may benefit from eating less meat.
So does it make sense to eliminate meat altogether for our companions – the cat as a carnivore, or our dogs, the opportunistic omnivore?
Dogs
It is not uncommon for people to feed their dogs a predominantly meat diet, with many basing their choice on the dogs’ ancestral connection to the wolf. However, the domesticated dog has evolved through selected breeding for particular favoured traits resulting in significant differences between wolves and domestic dogs, specifically in their behaviour and digestion. Unlike wolves, the domesticated dog has the ability to readily breakdown, absorb, and utilise carbohydrates.
In other words, dogs are not solely dependent on meat as were their predecessors. With their ability to produce enzymes that help breakdown dietary starch, they are able to digest both the animal and plant components of their food. But remember, despite their ability to digest plant material, good pet nutrition is only possible when it is complete and balanced. To ensure a plant based diet meets the optimal nutritional profile, dietary supplements such as vitamin B12 and certain amino acids, such as taurine, may be necessary.
Cats
Cats on the other hand are obligate carnivores, meaning only a meat-based diet will provide their unique nutritional requirements.
Cats have very specific needs for certain amino acids and essential fatty acids, with a high requirement for both vitamin A and certain B vitamins. These demands cannot be met by a vegetarian or vegan diet as plant-based ingredients simply do not provide all of the essential nutrients cats need.
But isn’t a protein a just protein?
What difference does it make where the protein comes from? The body is composed of many different types of protein made up of specific building blocks called amino acids. Amino acids are classified as either nonessential being synthesised by the body or essential requiring their availability in the food. Animal sources provide a complete source of protein (i.e. containing all essential amino acids), whereas vegetable sources generally lack one or more of the essential amino acids. For instance, taurine is a specific dietary amino acid that is essential for cats. Dogs (and humans) are able to synthesise taurine, but cats cannot. It must therefore be provided through their diet and taurine is only available from animal sources. Insufficient levels of taurine can lead to the development of heart disease, and vision problems.
Having said this, amino acids are not the only essential nutrients for which a plant based diet is inadequate.. Others include vitamin D, vitamin A, and arachidonic acid.
You may have heard vitamin D referred to as the “sunshine vitamin”. When people are exposed to the sun their bodies start to make vitamin D. Cats lack this ability, hence the need for it to be provided in their food. This can only be achieved through animal sources as plant levels are insufficient.
With vitamin A, some species can synthesise the active form from beta-carotene, which is found in plant-based ingredients such as carrot, sweet potato and pumpkin. Cats are unable to do so, meaning they need to acquire it through the consumption of meat, which contains pre-made vitamin A.
Arachidonic acid is an essential omega-6 fatty acid that helps combat inflammation. Dietary sources include meat and eggs, but not plants.
As a result of these unique dietary requirements, without supplementation a cat is unable to safely eat a vegetarian or vegan diet. Even with supplementation, feeding cats a vegetarian diet can have serious health implications. Cats must eat meat.
If a vegan lifestyle is your choice, enjoy the benefits it brings you, but your cat cannot and will not be healthy or happy eating the same way. The omnivorous dog will flourish if you choose a diet inclusive of both animal and plant sourced ingredients.
If you enjoyed this blog, check out Pet food myths and misunderstandings
Dr Penny Dobson BVSc MACVSc (Canine), Hill’s Helpline Manager
Penny has worked as a clinician in small animal practice Sydney Metropolitan area for 30 yrs and is a Veterinary Practice owner with her husband, Paul Hansen of Woollahra Veterinary Hospital. She has worked as a clinician in small animal practice Sydney Metropolitan area for 30 yrs and is a Veterinary Practice owner with her husband, Paul Hansen of Woollahra Veterinary Hospital. Penny has been involved in the Australian Veterinary Association (AVA) as Secretary Sydney Metropolitan Practitioners Branch for 12 years and recipient of the AVA Meritorious Service Award 2002. She is also an active member of the ASAVA. Nutrition is a passion for Penny and she is the Hill’s HelpLine Manager with the Veterinary Nutritional Consultancy team with a focus on uroliths, kidney, obesity, immune diseases and their management.