Is EA sleeping on making dogs and cats vegan?

Alistair Stewart

New paper on plant-based diets for companion dogs and cats: Sustainable Pet Diets: A Leading Effective Altruism Issue.

The paper argues that transitioning companion dogs and cats to plant-based diets is:

Important – a full global transition would apparently spare around 7 billion land animals each year (and reduce environmental harm, and improve food security).
Tractable – 13 to 19% of guardians are open to plant-based diets for their dogs/cats if their concerns are addressed, according to two recent surveys.
Neglected – annual global funding for tranisitioning companion animals to plant-based diets is well below $1m.

If the numbers hold up, the case seems strong! But I'm curious about the counterfactual impact of transitioning companion cats and dogs to plant-based diets, especially given that humans wouldn't eat or use some of the animal-derived food that companion animals are fed. What do people think about that, and how do the numbers and arguments look in general?

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Ben StevensonFeb 2015

Thanks for sharing, Alistair! I recently spent some time looking into this issue, and I don’t think it’s a good EA cause area. Pet food does directly result in the farming of more livestock that I had expected, but Knight overstates his case and doesn’t engage with the rest of the literature.

On scale:

a full global transition would apparently spare around 7 billion land animals each year

This is not true. The paper linked doesn’t explain Knight’s methodology, but if you click through to Knight (2023) you’ll find that the author double-counts a lot of livestock carcasses. Copy-pasting my earlier notes because I’m dashing this comment off, hope it makes sense:

In particular, it claims: "Human meat consumption is responsible for this many animals being farmed directly. And pet food meat consumption is responsible for this many animals being farmed directly, and this many animals being farmed indirectly (i.e., byproducts)". The total sum of animals therefore double counts the animals who are farmed for both human and pet consumption.
[…]

Andrew's model in the 2023 paper assumes that animals farmed for pet food ~= animals farmed directly + (ABPs [animal by products] * R), where R is basically the ratio of ABP:meat in an animal body. (I know I'm oversimplifying because he also includes a co-efficient to account for food waste, and so on). This formula means that (a) when put alongside animals farmed for human food, we're double-counting the animals whose bodies mostly are eaten by people and minorly eaten by pets, and that (b) ABPs are always assumed to have a greater cost in animals lives than meat, which reverses the causal relationship. Byproducts don't drive production.

The byproducts point is important to appreciate whether, setting the numbers aside, vegan pet food would counter factually reduce the number of animals being farmed. Knight claims that there are other economically productive uses for byproducts; if that’s true, then a reduction in demand for animal-derived pet food would change the marginal use case for byproducts but not reduce their production. That undercuts Knight’s point on scale because so much of the scale falls out of inflated byproduct numbers.

On tractability:

I haven’t dug into the surveys that Knight cites but I’m super skeptical. I know vegans who don’t have vegan pets, and I know how hard it is to make people go vegan. There are big barriers to getting humans to transition to alternative proteins at scale, and that’s only more true for companion animals.

On whether this is EA:

I’m super pleased that some people have looked into this, and I think being able to entertain weird ideas seriously is a great thing. I even think there could be some cool stuff in this space (campaigning for cats and dogs to eat less chicken and fish?).

But to be an EA issue — especially a ‘leading’ issue — it has to be more cost-effective than other good opportunities, and I don’t think it is.

Seth Ariel Green 🔸Feb 204

I agree, Ben, that tractability is low. I am also a bit skeptical of anything saying cats can be vegan without a lot of qualifications.

However I did a bit of research into the "how many animals are actually killed for dog food" in 2023 and I got to about 3 billion/year using a bunch of approximations: https://forum.effectivealtruism.org/posts/zihL7a4xbTnCmuL2L/towards-non-meat-diets-for-domesticated-dogs. So that's not 6 billion but it's still a lot. And I'm also just talking about dogs.

I also think that ABPs, if they didn't go into dog food, would just go into something else. I think it is a mistake to think that demand for ABPs does not drive demand for meat. The "byproduct" designation is convenient when distinguishing animal parts of different value, but at the end of the day, if you're paying someone for animal parts, you're paying them to slaughter animals. Here's a little bit I wrote about this for an op-ed I never published:

Dog food is responsible for a large amount of environmental harms — tens of millions of annual tons of CO2 in the U.S. alone — because dogs are numerous, relatively large animals who eat a lot of animals, and animal agriculture is a major contributor to climate change. This is true even if they’re eating mostly animal byproducts (ABPs).

Still, ABPs may drive less animal agriculture, and therefore less environmental damage, than meat itself. The more we pay people to farm animals, the more they’ll do it. ABPs are worth less than meat. Shifting from byproducts to meat increases demand for slaughtered animals.

A 2020 paper by Peter Alexander and colleagues provides a framework for measuring this increase. The authors find that typical dry dog food is composed of roughly 32% ABPs, 16.3% animal products, and 47.9% crop products. They calculate environmental harms based on an “economic value allocation method, where the environmental impact[s] of producing an animal are allocated in the same proportion as the value of the products.” ABPs, they conclude, produce about 12-18% of greenhouse gas emissions associated with dry dog food, despite being about a third of such products by weight.

The Alexander et al. (2020) paper was about the best thing I could find on the subject in general.

Ben StevensonFeb 204

Thanks Seth (good to hear from you)!

I agree with everything here. In particular: a lot of animals are farmed directly for pets, and ~3 billion sounds like a reasonable guess (I think Knight is double counting with ~7 billion). This was an update for me when I looked into this because I had thought almost all pet food was byproducts.

And I might be understating the scale case because I’m bugged by the methodology. But I don’t think the scale case is compelling when we think in terms of animals who could reasonably be taken out of the food system by vegan pet food, instead of number of animals farmed for pet food. This is something that motivates my (stray) thought that promoting beef > chicken/fish for companion animals could be high impact.

I like the Alexander paper but I think economic allocation makes more sense when you’re trying to attribute environmental harms than when you’re trying to reason about the number of animals killed in a counter factual scenario. Looking at the tools from LCA, I’d like to see somebody try a system expansion model here!

Please share the draft with me, I’d like to read it!

GeorgeBridgwaterFeb 201

Intersting previous post! I think your caculations work similary assuming 100% of the demand for meat in pet food translates to farmed animals. The effect of a decrease in demand for ABPs on the number of farmed animals will be less than 1-1. Based on the Peter Alexander paper that would suggest a 45% to 63% discount on the contribution. (Which brings your number down to more like 1-2 billion, still alot in absolute terms). Although even then its more of a simplifying assumption as the real decrease would depend on counterfactual uses and how shifts in demand and prices eventual wash out. You also don't include fish or developments for insects that could boost the numbers back up the other way.

Although I don't think total numbers is main crux. Importance or neglectedness are only really good proxies for wether to look into an area which I think the case for vegan pet food has done fairly well.

Tractablity is very important. If we survey humans similary for are they open to plant-based diets we get a similar high or higher number, "38% of German and UK adults intend to change their diets by eating more plant-based foods". Broad intentions are not a great indicaiton of how cost-effective interventions to talk with pet owners, pet food companies or goverments to transition would be. For 1-1 outreach I'd expect targeting pet owners to be less effective than vegan outreach just for the fact that 2/3 of people won't be relevant.

I think more informative direction for future research in this area would be to do target research and some inital conversations and testing. I'd want to see that:

1. companies are shifting a large enough volume of product (when discounted for the ABP effect on overall demand for animal farming) that targeting this could plausibly be worthwhile
2. work with Pet food companies, retailers or other institutions to shift proportions of ingredients in food to be more plant-based for better animal welfare and climate outcomes seems tractable as a campaign. Thinking why they would do this? Would people support action against them if they don't? Are there other incentives we could use?
3. It does not backfire. We would have to watch out the small animal replacement problem if they shift to chicken or fish for climate reasons.

Maybe there are potential cost-effective campaign targets but high meat proportion is usually a selling point for pet feeds. At the moment i'd expect running a campaign like that would be more difficult relative to how important the campaign target is compared to the marginal cage-free or broiler campaign.