Comparison of meat- and plant-based food for Cats

[article updated with Dr. May's video below]

The word vegan for many is associated with tomatoes, cucumbers and other veggies. When thinking of cats we think carnivores, hunters and sharp instincts. No wonder then that putting the two words - vegan and cats - in the same sentence has been the subject of many heated debates.

In this blog post we'll reconcile the two words in 3 ways:

1. by comparing two formulas - a meat-based formula and a vegan formula
2. by peaking into a recent study
3. by looking at other considerations

Comparison of two formulas

The meat-based formula in our comparison is a typical cat food formula - Purina Friskies Savoury Selections. The vegan cat food formula is Evolution Diet Gourmet Fondue. To help with the comparison we'll group the ingredients in three categories:

1. animal-based sources - provide proteins and fats
2. plant-based sources - provide proteins, fats, carbs and fibre
3. produced in a lab - vitamins and minerals and certain amino-acids

As carnivores, cats require specific nutrients: protein, fat, fibre, fatty acids (such as arachidonic acid), vitamins (A, B2, B3, B12, E etc), amino acids (taurine, arginine etc) and many others. 

Veterinarian Dr. Armaiti May states “Cats and dogs have Nutrient requirements, which are not the same as Ingredient requirements.”

The implication here is that although cats are carnivores, they do not need specific ingredients (such as meat or fish) and instead they require specific nutrients (such as specific amino-acids).

The table below helps us understand where these nutrients come from in each formula.

The first glance at the table immediately tells us that vegan cat food is not simply a salad mix, it is an advanced formula composed of numerous ingredients. Furthermore, note that in both formulas the majority of ingredients are actually made in the lab (third section in the table). Notably, taurine, an amino-acid critically important for cat's eye-sight and cardiovascular function, is produced in the lab and added to both diets. The heavy supplementation in both diets is the result of compliance with AAFCO cat food standards. AAFCO prescribes that cats have to have certain amounts of vitamins and minerals and hence the heavy supplementation.

Furthermore, both formulas obtain protein (wholly or partially) from plant-based sources. For example, soybean meal and corn gluten meal in Purina are rich sources of plant-based protein, and that contributes to the overall protein content in that meat-based formula. So using plant-based proteins is not a new practice - the meat-based kibbles have been using them for a long time. Of course Purina also contains meat-, bone-, fish- and turkey-meals, while Gourmet Fondue does not. The question then is if we are to source proteins from plant-based sources alone - will the cat be ok?

To answer that question we'll need to look at protein structure. Proteins are composed of amino-acids. 

AAFCO prescribes the "ideal" amino-acid profile for obligate carnivores. 

The only essential amino-acid for cats that is hard to find in plant-based sources is taurine. All other amino-acids can be found in plants in abundance. And so the only way to meet the taurine requirement for vegan cat food is to add synthetic taurine. Adding synthetic substances doesn't sound very natural, however, Purina and all other producers also add synthetic taurine in meat-based foods, because during the manufacturing process the natural taurine is baked off from animal ingredients due to high temperature and pressure. As a result, both formulas use synthetic (vegan) taurine. And with this addition the amino-acid profile of plant-based proteins becomes complete and 100% sufficient for cats. 

By comparing the two formulas we have established that

• properly balanced vegan cat food is not a salad mix, but rather an advanced formulation
• the majority of the ingredients in both formulas are actually made in the lab (to meet AAFCO standards)
• both meat- and plant-based kibbles utilize plant-based proteins, which are very much digestible and palatable
• the amino-acid profile of plant-based proteins becomes complete with the addition of the synthetic taurine, which is used in both meat- and plant-based diets

Overall, looking at the fundamental nutritional blocks - proteins, fats, minerals and vitamins - the two formulas are not that much different and meet the requirements of AAFCO.

Recent study

The above comparison provides a good theoretical foundation, however, to make the definitive argument it would require the support of practical experimentation, which is why we wanted to see if studies have been done with cats and vegan cat food. There are not many studies, however, there is one recent study (1) - see references below - that looked into vegan diets for cats. The study concluded that

"Both cats and dogs may thrive on vegetarian diets, but these must be nutritionally complete and reasonably balanced."

One word of caution from the study is that

"Owners should also regularly monitor urinary acidity, and should correct urinary alkalinisation through appropriate dietary additives, if necessary."

This is a great segue to our next section.

Other considerations

Urinary health

A plant-based diet contributes to making a cat's urine more alkaline. In itself it's not a problem, however, in male cats urine with more alkaline pH can lead to the formation of struvite crystals in the urinary tract (a mixture of magnesium, ammonium, and phosphate), which in turn can lead to urethra obstruction.

To bring urine pH back to normal, cats (especially male cats) need to be supplemented with acidifiers, which dissolve the struvite crystals. Most popular vegan dry kibbles (Evolution Diet and Ami) and meat-based diets (see the table above) are supplied with ingredients like DL Methionine and other ingredients to help keep acidity in the 6.0 - 6.5 range. So again, in that regard the two formulas are not different as both rely on an additive - DL Methionine - for pH balance. See more information about urinary health in this article.

Recalls

One fact that definitely sets the two formulas apart is the risk that comes with meat-based diets. Regular meat-based cat and dog food is notorious for poisonings and recalls. This page shows that there were over 200 reported recalls since 2008. 73 out of 200 cases are the Salmonella contamination cases. Salmonella is a bacteria found in raw meats, eggs and poultry. In most meat-based formulas the quality of meat is very low (discover why the quality of meat is low here) and keeping the meat safe is a big challenge. Vegan formulas, on the other hand, have no meat-based ingredients, and therefore present a much lower risk of poisoning.

Externalities

The above comparison of two formulas and the study show nutritional adequacy (and in the case of recall safety - superiority) of vegan diets. Many cats have gone through the transition and they are doing really well. In addition, vegan diets are also better than the meat-based diets from the ethical and the environmental perspectives. 

In the making of meat-based cat foods there are 2 often-ignored factors (which I call externalities) -

1. an animal (a cow, a pig or a chicken etc.) had to be slaughtered in order to make cat food
2. a large dose of greenhouse gases was emitted in the process of growing the animals, and the gases ended up in the atmosphere thus contributing to global warming

With vegan diets no animals were killed and a small fraction of greenhouse gases was emitted. So if people were to consider the impact of these externalities for meat-based foods, then the vegan diet is the winner.

Cost and Availability

Currently the cost of vegan cat food is about twice the cost of regular meat-based cat food. This is counter-intuitive because generally meat-based ingredients are more expensive than plant-based ingredients. How can pet food be so cheap? This is almost entirely due to low quality of meat-based ingredients and due to the economies of scale. Availability of vegan cat food is currently limited. However, the cost of vegan food and availability will change as more people become aware of the alternatives with no externalities and lower risk of recalls. The more we can spread the word and raise awareness, the more cost effective and easily available plant-based cat food alternatives become. 

Conclusion

To conclude, commercial vegan formulas are carefully formulated to meet the nutritional requirements of cats and are not simply a salad mix. The apparent contradiction of the words cat and vegan is not a contradiction if you compare meat- and plant-based formulas side-by-side, consider safety and the externalities of modern cat foods:

• From nutritional perspective
• when properly balanced, vegan diet is healthy for cats and a recent study supports this
• cat guardians, however, should be cautious to monitor the pH of cat's urine to avoid urinary health issue - this applies to both vegan and non-vegan diets
• From the recalls and safety perspective
• vegan diet is safer than meat-based diets
• From ethical and environmental perspectives
• vegan cat food is superior
• From cost and availability perspectives
• meat-based cat food is cheaper and readily available in stores

References

(1) Vegetarian versus Meat-Based Diets for Companion Animals Andrew Knight and Madelaine Leitsberger, Centre for Animal Welfare, University of Winchester, Winchester SO22 4NR, UK; Published: 21 September 2016

Related Products

	Gourmet Fondue - formulated to meet the nutritional levels established by the AAFCO cat food nutrient profile for all life stages
	Maximum Life - plant-based vegan cat food; grain free, gluten free, 100% non-GMO and is formulated for your cat's maximum health
	Ami Cat food - plant-based vegan cat food formula from Italy - complete, balanced formula, ideal for adult cats, and made from 100% plant-based sources with no artificial dyes or preservatives
	Moist Food in Cans - used to provide adequate hydration, which in turn helps avoid urinary tract issues, and to ensure that Urine Specific Gravity stays at normal levels
	Cranberry Treats - used as acidifier to dissolve struvite crystal and to lower pH; also used as a delicious cat treat
	VegeCat Phi - used as a supplement for vegan home-made meals; contains an acidifier Sodium Bisulfate, which helps making alkaline urine more acidic
	VegeYeast - used to enhance the flavour as well as to acidify the food to make alkaline urine more acidic
	Nutritional Yeast 'Cheesy Chic'n' flavour - used to enhance the flavour of cat food. Cats go crazy about it!

Disclaimer Notice

The contents of the vecado.ca website and blog, such as text, graphics, images, and other material contained on this site ("Content") are for informational purposes only. The Content is not intended to be a substitute for professional veterinarian advice, diagnosis, or treatment. Always seek the advice of your veterinarian with any questions you may have regarding the medical condition of your pet. Never disregard professional advice or delay in seeking it because of something you have read on this website! Reliance on any information appearing on this website is entirely at your own risk.