Alligators and Cats - What do they have in common?

studies show that both alligators and cats can be fed a plant-based diet

Alligators and cats have tails, yes, but that’s not it.

Sharp teeth? Getting closer!

They are carnivores! You almost got it!

2017 and 2021 studies about American alligators and domesticated cats, respectively, show that these predators can be successfully fed plant-based diets.


DiGeronimo et al in their 2017 study say: “No differences were found between alligators fed diets with animal or plant protein in terms of either biochemistry profiles or gross or histologic examination of kidney and liver. Plant-based diets, fed for up to 10 mo, do not appear to have any ill effects on the kidney or liver of American alligators.

Dodd et all in their 2021 study say: “the health and wellness of cats does not appear to be adversely affected by being fed a plant-based diet. Contrary to expectations, owners perceived no body be at particular risk when feeding a plant-based diet to cats.” 

Both of these studies help us understand the point that the key to sound nutrition is the nutrients, and not the ingredients per se. Carnivorous animals require specific nutrients, which can be derived exclusively from plant-based ingredients or supplemented.

"Nutrients over Ingredients" sounds good in theory, but does it work in real life?

The Dodd et al 2021 study collected data on 782 real cats and explored how long and how well cats live on a plant-based diet.

The results were surprising to the researchers.

The hypothesis was that cats on a PB (plant-based) diet get sick more frequently and don’t live as long as cats on a MB (meat-based) diet.

However, the collected data could not confirm shorter lifespan, prevalence of diseases, or the ‘unhappiness’ for cats on a PB diet.

Instead, the researchers found that cats on a PB diet live just as long as cats fed a MB diet (see the animation for 2 cat groups after 10 and after 20 years:

The thriving aspect / wellness and happiness of cats was evaluated based on the following 7 metrics, and cats fed a PB diet show slightly better scores than cats fed a MB diet (evaluating these 7 criteria helps reducing the subjectivity in determining cat's happiness; furthermore, the law of numbers apply - the greater the sample size, the more statistically significant the results, and in this case 782 real cats were surveyed, and such sample size provides statistically significant results)

  • appears to be happy overall

    • MB 59% vs. PB 65%

  • demonstrates affection

    • MB 74% vs. PB 88%

  • curious

    • MB 49% vs. PB 50%

  • content / at ease behaviour (absence of distress vocalization)

    • MB 80% vs. PB 85%

  • infrequent vomiting

    • MB 59% vs. PB 65%

  • active

    • MB 74% vs. PB 88%

  • wants to spend more time with humans (absence of contact avoidance)

    • MB 70% vs. PB 79%

This research connects nicely with the prior research on vegan pet foods for cats (see reference section on Vegan Cats 101 page). The previous studies point to a general conclusion that cats can adopt a complete plant-based diet without any negative consequences for their health.


Nutritional science has gone a long way in understanding the nutritional requirements of cats, dogs, alligators, and other species. And these nutritional requirements can be met with plant-based ingredients and supplementation.

From the 2 studies (about American alligators and domesticated cats) we conclude that complete PB diets work fine for both species.

Finally, the 2021 Dodd et al study also suggests that plant-based diets provide similar lifespan for MB and PB cats. Moreover, the study demonstrated similar happiness scores for PB cats and MB cats. So PB cats not only can survive on a PB diet, but can also thrive!


The alligator study was performed in relation to farmed alligators.

Vecado does not support alligator farming in any way.

The mentioning of the alligator study here merely goes to illustrate that if such primordial hunters as alligators can be successfully fed a plant-based diet, then feeding cats, also obligate carnivores, may not be as novel or unconventional as commonly considered.


See if the plant-based diet is right for your cat or dog.

[Assessment link]


  1. DiGeronimo P, Girolamo N, Crossland N, et al. Effects of plant protein diets
    on the health of farmed American alligators (Alligator mississippiensis). J Zoo
    Wildlife Med. 2017;48(1):131–5.

  2. Dodd, S.A.S., Dewey, C., Khosa, D. et al. A cross-sectional study of owner-reported health in Canadian and American cats fed meat- and plant-based diets. BMC Vet Res 17, 53 (2021).

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