Should you put your pet on a vegetarian diet?

With society's mounting awareness and concern for climate change, animal welfare, and the environment, more and more people are adopting a vegan or vegetarian diet for themselves these days. And consequently, as education around the topic grows, a growing interest is emerging in the idea of meat-free diets for our pets too.

Many cat and dog owners who opt for a meat-free lifestyle find themselves in the middle of a true ethical quandary - how can I maintain my ethical standards, yet still feed a meat-based diet to my carnivorous pet?

When the statistics are analysed, it's not surprising that so many people make the decision to cease their support of the meat industry. Over 70 billion terrestrial animals are slaughtered annually, and trillions of fish are also killed annually to feed the western world's ravenous desire for meat. High density living conditions, artificial genetic selection, and invasive husbandry procedures all contribute to a serious and very real animal welfare concern for all farmed species. In addition, the environmental impacts of animal agriculture are highly deleterious, and the industrialisation of the meat industry has been demonstrated to be an important contributor to climate change.

But while plant-based diets have been demonstrated to be sufficient for an adult human, can the same be said for cats and dogs? Is it possible to provide a balanced diet to a cat or a dog without the inclusion of meat?

It is estimated that there are 1.5 billion vegetarians globally, 75 million of which are vegetarians by choice (compared to those in developing countries who are vegetarians due to necessity). The number of voluntary vegetarians and vegans is predicted to increase, and so too will the number of pet owners who wish to feed their pets a vegetarian diet.

Aren't cats and dogs carnivores?

Before we delve into a discussion about vegan or vegetarian diets for pets, let's take a look at the animals themselves and their nutritional requirements.

Dogs are omnivores. Contrary to popular belief, dogs are omnivores; not carnivores. Yes, the domestic dog (Canis lupus familiaris / Canis familiaris) belongs to the order Carnivora, but they are actually an incredibly evolved species.

But... wolves?? - A popular train of thought in the pet food world is that dogs should be fed a diet as close to their wild ancestors, the Grey Wolf, as possible. This 'ancestral diet' theory argues that the dog's anatomy (ie teeth designed for cutting and slicing, shorter intestinal tracts) is built for a carnivorous diet.

However, dogs were domesticated by humans approximately 33,000 years ago, and consequently have evolved considerably. To adapt to a life alongside humans with a more varied diet, dogs evolved a number of features that allowed them to digest plant-based foods. These features include an increased gene expression for pancreatic amylase, the ability to convert maltose to glucose, and increased uptake of intestinal glucose. Early wolves had none of these genetic abilities. Therefore, dogs can well and truly be considered biologically omnivorous.

In fact, dogs share only 98% of their DNA with wolves - about as much as humans share with bonobos. If you don't feel that your diet should mirror a bonobo's (or hey, maybe you do like a quasi-vegan-insectivorous diet?) - then we really shouldn't argue that dogs need to be eating like wolves purely due to DNA similarities.

Cats, on the other hand, are obligate carnivores. Cats were domesticated 10,000 years ago, partly for the purpose of hunting pests. It makes sense therefore that the pressure on cats to adapt to mixed human food diet was less than that applied to dogs. As a result, cats generally lack the genetic adaptations to thrive on an omnivorous diet.

There are certain nutrients that cats simply cannot metabolise from plant sources. For example taurine, an essential amino acid, must be obtained from an animal source. While dogs can make taurine from plant protein, cats do not possess the biological ability to do this and require meat for this.

What are the risks of a vegan diet?

While dogs can thrive on an ovo-lacto vegetarian diet, the main risks that must be addressed when considering a vegan diet for cats and dogs include:

  • 1. The balance of amino acids. Of particular concern for both cats and dogs are taurine and L-carnitine. Arichidonic acid is also a concern, but for cats only.
  • 2. Adequate total protein intake. On average, plant material is lower in protein percentage than meat (with some exceptions).
  • 3. Vitamin and minerals - namely B vitamins, calcium, phosphorus, and iron. These micronutrients are ideally obtained through meat or animal products and can be hard to provide in plant-based ingredients alone.

How to safely feed your pet a meat-free diet

For owners who wish to explore a meat-free diet for their pet, there are a number of options. Whether you prefer home cooking, or the convenience of a ready-made diet, there is something to suit everyone's lifestyle and budget.

Although diligent attention must be paid to ensure adequate levels of nutrients are met, there is (at least, in theory), no reason why diets comprised of non-meat ingredients cannot meet the nutritional, palatability and bioavailability requirements for cats and dogs.

1. A Commercially Available Vegetarian Diet

See All Vegetarian Diets

Compared to home cooking, a commercial diet is much more likely to be complete and balanced for your pet (particularly if it is a top quality diet from a premium brand).

Unfortunately commercial vegetarian or vegan commercial diets are rare and hard to find in Australia. However, you might be surprised to hear that some veterinary prescribed diets for allergies are actually vegetarian. These aren't formulated as meat-free for ethical reasons, but rather, it just so happens that in creating a hypoallergenic diet for allergic dogs, often a vegetarian diet is necessary. Read more about why this is the case in Dr Kim's article on hypoallergenic diets.

Proplan Veterinary Diet HA is formulated for dogs with common allergies, and uses hydrolysed soy protein instead of animal meat. It would almost be considered vegan, except for the inclusion of fish oil.

Royal Canin Hypoallergenic utilises soya protein isolate as its protein source, and Royal Canin Anallergenic uses poultry feather protein instead of meat. However, both contain small amounts of animal fat, and Hypoallergenic contains poultry liver, so neither of these are appropriate if you are looking for a vegan or completely plant-based diet.

Diets that fall into this category are Prescription and Veterinary diets and can therefore only be recommended by your veterinarian. If you are interested in these diets, we recommend chatting to your vet about whether they are appropriate for your dog. If your vet doesn't think they are suitable for your pet, you might need to wait until more commercially available vegetarian pet foods come to the Australian market!

As yet, there are no vegetarian diets commercially available for cats.

Your Vet May Recommend:

Royal Canin Veterinary Diet Anallergenic:
Protein source: A hydrolysed feather protein (also contains animal fats)
Recommended for: This diet is formulated for the purpose of diagnosing and managing food allergies in sensitive dogs. It is formulated to be completely balanced in line with international pet food standards, and undergoes diligent research and development in Royal Canin's facilities.

Royal Canin Veterinary Diet Hypoallergenic:
Protein source: Hydrolysed soy (also contains animal fats and poultry liver)
Recommended for: The diagnosis and management of food allergies. It may be more cost-effective for large breed dogs who tolerate a soy-based diet.

Proplan Veterinary Diet Hypoallergenic:
Protein source: Hydrolysed soy protein (contains fish oil)
Recommended for: The diagnosis and management of food allergies. Depending on your method of classification, this diet is either vegetarian or pescatarian.

2. A Commercially Available Pescetarian Diet for Pets

See All Pescetarian Diets

What is a pescetarian diet? 'Pescetarian' is the term used to describe a diet free from meat, except for seafood. (Ever heard someone call themselves a 'vegetarian who eats fish'? The term they should be using is 'pescetarian'!)

If you are open to feeding a pescatarian diet to your pet, you are in major luck. There is an extensive array of diets available these days made with fish that are free from any other types of meat.

Hot tip: fish-based diets are often found to help dogs with skin issues. Due to the high concentration of beneficial fish oils, combined with the fact that they are free from most common allergens (chicken / beef / dairy / and often grains) many dog owners notice an improvement in skin and coat quality.

When selecting a pescatarian diet, it's important to carefully assess the entire ingredients list to ensure no other meat sources, such as poultry oil, are included.

Our Top Pescetarian Picks:

Pescetarian Food for Dogs

1. Billy + Margot Salmon and Superfood Blend:
Protein source: Fresh salmon

This top quality food from Billy + Margot has a single-source animal protein claim, so you can be sure that no other meat sources are present in the recipe (just salmon!). It is Australian-made, and one of the few diets on the market that includes either raw or fresh fish as the number one ingredient, as opposed to fish meal.

2. Ivory Coat Ocean Fish Dry Dog Food
Protein source: Fish, salmon

This dry food from Ivory Coat is completely pescetarian, and is very popular among owners of dogs with skin issues. It is Australian-made and grain free, and its high palatability means it is good for tempting fussy eaters.

3. Canidae Pure Sea
Protein source: Salmon, menhaden fish

This fish-based kibble from American brand Canidae is another great pescatarian diet, and is also very popular among owners of dogs with skin issues. It is well reviewed by scores of dog owners with itchy skin, and is known for being highly palatable.

Pescetarian Food for Cats

1. Artemis Osopure Salmon and Garbanzo Bean
Protein source: Fresh salmon, salmon meal

This top quality food from Artemis Osopure contains salmon and salmon meal, which means it is technically a single-source protein diet (ie, it doesn't mix different species of fish). This is good if your kitty has possible allergies.

2. Taste of the Wild Canyon River Feline Formula
Protein source: Trout, Ocean Fish, Smoked Salmon

This dry food from American brand Taste of the Wild is completely pescetarian and grain-free, using trout, ocean fish meal, smoked salmon, and sweet potatoes.

3. Canidae Pure Stream
Protein source: Trout, salmon, menhaden fish

This fish-based kibble from American brand Canidae is another great pescatarian diet for cats. It is well reviewed and is known for being highly palatable.

As more and more pet foods come on the market, particularly ones with exotic and unusual protein sources, more and more pescetarian varieties are emerging. If you are happy to feed a pescatarian diet, check out our entire range of pescetarian and fish based diets.

3. A Home-Cooked Diet

What about home-cooked vegetarian diets for pets? Preparing your pet's food at home might sound like a good option and there are certainly some benefits. By preparing your pet's food at home, you know exactly what is going in to the food, and can be sure there are no hidden pet food additives.

However, it is notoriously difficult to prepare a meat-free diet that is complete and balanced for your pet, and you will without a doubt need help from a veterinary nutritionist. If you are set on home cooking, advice from a veterinary nutritionist might cost you a consultation fee; but it will be worth it in the long run. Think of it as an investment in your pet's health - and it's not much compared to how many vet bills it will likely save you in the future due to a diet lacking in nutrients!

Most veterinary nutritionists are happy to set you up with some vegetarian recipes - especially if you are happy to include eggs in your cooking - and may suggest a ready-to-use, mix-in vegetarian chaff such as Vets All Natural Complete Mix. Eggs are actually one of the most nutritious and bioavailable forms of protein for dogs, so if you are open to including eggs in your recipe, your dog will reap the benefits. It will also help with palatability! (Don't forget to make sure they're free range!)

What are the drawbacks of a home-cooked vegetarian or vegan pet food diet?

  • Difficult to balance without the help of a veterinary nutritionist
  • Not recommended in growing animals and cats, or animals you intend to breed
  • Not recommended for long-term feeding
  • Expensive - the cost of ingredients (and your time!) is usually greater than buying a commercially made diet

The bottom line is this - a vegetarian diet, particularly one incorporating eggs, is definitely possible for dogs and is not as dangerous as once believed. However, it really is tricky for cats; and at this stage, we don't recommend cutting out meat from your cat's diet. Perhaps consider a pescatarian diet for your cat, or consider a different pet altogether. Which brings us to our next point...

After a completely awesome, and totally vegan, furry friend? Why not adopt a rabbit?! We love rabbits so much that we made a video about why rabbits make great pets - and even have an article on how to litter train your rabbit which helps make them a totally apartment-roaming, free range little buddy!

Further Reading: Research on Vegetarian and Vegan Dog and Cat Food

It's all well and good to read anecdotal stories about the benefits, or deficiencies, of meat-free pet food diets. But what does the research say?

Studies looking at whether vegetarian pet food meets nutritional requirements: It's easy to assume that commercial vegetarian diets will be more likely to be deficient in certain nutrients than meat-based diets. However, research from the USA into the regulations, quality control and testing procedures of a wide variety of pet food brands proved that nutritional inadequacies are just as commonly found in meat-containing lines of pet food, as they are in their commercial vegetarian counterparts. Ultimately, there is a spectrum of low to high quality food for both meat and vegetarian-based diets and every diet should be considered on a case-by-case basis. Read more about this here.

Studies into the health of vegetarian pets: There is an increasing body of evidence that suggests that the health of cats and dogs fed commercial vegetarian or vegan diets can be well-maintained, and that vegetarian cats and dogs can even thrive. However, it should be noted that dogs are over-represented in these studies compared to cats, and as yet not many of the studies are considered to meet the cornerstones of gold standard evidence-based medicine.

This study by Semp (2014) in Europe used blood tests to evaluate the health of a number of vegetarian cats and dogs, and no significant concerns were found.

Brown et al (2009) examined a number of sprint-racing Siberian Huskies and found that those fed a vegetarian diet for 16 weeks showed no detectable health problems or anaemia, compared to a control study fed a meat-containing diet.

Wakefield et al (2006) measured the blood taurine and cobalamin levels of a number of cats fed commercial vegetarian / vegan diets and found no significant abnormalities.

Interestingly, most of the more negative studies that found a vegetarian diet will negatively affect pet health are usually older studies, based on older formulations of vegetarian pet food.

In general, the more recent the research, and the more it is based on modern commercial balanced diets, the more likely it is to be positive. It may be assumed that as the pet industry evolves, and the more balanced vegetarian diets brought to market, the more likely research is to be positive.

Posted by Dr. Carla Paszkowski

Dr Carla is one of our resident Pet Circle veterinarians. She has a special interest in feline medicine and pocket pets. As the owner of one very fluffy, cross-eyed Ragdoll named Smudge, Carla loves all things cat-related and is proud to be a self-professed 'crazy cat mum'.

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