Effective Altruism for Animals: How to Have the Most Impact

Published by Animal Welfare Hub — evidence-based information to improve animal lives
Effective altruism asks: given that we want to do good, how can we do the most good? Applied to animal welfare, this means asking which interventions actually help the most animals, which charities deliver the best outcomes per dollar, and how to think rigorously about where your time and money will do the most good. This guide synthesizes the best available research.

Why Scale Matters: The Numbers Behind Animal Suffering

Approximately 80 billion land animals are raised and slaughtered for food every year globally. The majority of these are chickens, living in conditions that cause significant suffering. In marine fisheries, hundreds of billions to over a trillion sentient fish may be caught annually. These numbers dwarf the scale of suffering in almost any other domain of animal welfare. Effective animal advocates focus their efforts where they can affect the greatest number of animals, which means looking carefully at food systems rather than focusing exclusively on companion animals or charismatic megafauna.

The Most Cost-Effective Interventions

Research by organizations such as Animal Charity Evaluators (ACE) and Rethink Priorities consistently identifies corporate animal welfare campaigns as among the most cost-effective interventions available. Campaigns that persuade major food companies to adopt welfare commitments (such as the Better Chicken Commitment) can affect millions of animals per year with relatively modest organizational budgets. Leafleting and online advertising to encourage dietary change also show measurable impact. Farmed fish and invertebrate welfare is increasingly recognized as a highly neglected cause with enormous scale.

Thinking About Neglectedness and Tractability

Effective altruism uses three criteria to evaluate cause areas: scale (how many are affected?), neglectedness (how few resources are directed here?), and tractability (can we actually make progress?). By these criteria, farmed animal welfare scores very highly on scale and neglectedness but requires careful assessment of tractability. Wild animal suffering is even more neglected but less tractable. Companion animal welfare receives far more public attention and funding relative to its scale, suggesting the highest-impact advocates may focus on farm and aquatic animals.

How to Choose Which Charity to Support

Animal Charity Evaluators publishes annual reviews of standout animal charities, based on factors including evidence of impact, cost-effectiveness estimates, quality of research and strategy, and transparency. Top charities in recent years have included The Humane League, Wild Animal Initiative, and the Shrimp Welfare Project. When evaluating any charity, look for: evidence they measure their own impact, a clear theory of change, willingness to update their approach based on evidence, and financial transparency. Avoid charities that rely heavily on emotional appeals without evidence of effectiveness.

Career Choices and Animal Advocacy

80,000 Hours, an organization advising on high-impact careers, identifies animal advocacy as one of the most neglected cause areas relative to its moral importance. For people deeply motivated by animal welfare, careers in policy, research, corporate outreach, alternative protein development, or movement building can all be high-impact. Even outside of animal-focused careers, earning-to-give in a lucrative field and donating strategically can fund multiple full-time advocates. The key is to think carefully about counterfactual impact: what would happen if you specifically did not take a given action?

The Case for Focusing on Farmed Fish and Invertebrates

Rethink Priorities research suggests that farmed shrimp and fish likely experience significant pain and stress, and are raised in conditions that cause substantial suffering at enormous scale. Yet these animals receive a tiny fraction of the advocacy attention and funding directed at mammals. The Shrimp Welfare Project estimates it may cost as little as -0 to meaningfully improve conditions for 1,000 shrimp. If this estimate is even roughly correct, farmed invertebrate welfare may be among the highest-leverage areas in all of animal advocacy. This is a frontier cause that rewards early attention.

Effective altruism applied to animals asks us to think carefully, prioritize scale and neglectedness, and follow the evidence about what actually works. The conclusions are sometimes counterintuitive: the highest-impact interventions often focus on chickens, fish, and shrimp rather than the animals that capture our emotional attention most readily. But by thinking rigorously about where we can do the most good, we can multiply our positive impact for animals many times over.

Want to make a difference?

Explore our full library of animal welfare guides, or see our research on the most effective animal welfare charities for evidence-based giving recommendations.