1781 words • 10~16 min read

Is it time for a sustainable pet movement?

The world is rapidly approaching 7 billion people and the challenges of food supply, security, and sustainability will, along with climate change, be the defining issues of the 21st century. While the issues of the wealthiest nations revolve around the quality of our food, the environmental impact or our farming practices, and the value we place on a perceived degree of “naturalness”, the rest of the world is simply concerned with having enough to eat. What we chose to value in our society affects the rest of the world, and perhaps the most visible, and most dramatic difference between the developing and developed world is the ways in which we treat our pets.

The Problem with Pets

Beneath their cute, fluffy fur, pets in the developed world hide some very problematic truths about sustainability and economic growth. There are more than 76 million pet cats in the United States, and an estimated 47 million in Europe. This may not seem like much, but consider this: in a recent talk at the Ecological Society of America, Jason Clay of the World Wildlife Fund estimated that the average European house cat consumes 16 times more resources – food, water, energy – than the average human being living in poverty in Africa. Estimates like this should be taken with a grain of salt, but if we assume for a moment that they are generally close, then we’re talking about an additional 1.97 billion people. That means if you lose the cats, you could double the amount of resources available to the 2 billion people living on less than $2 a day.

Mind you, I’m not picking on cat people, those were just the most accessible statistics. All domestic pets consume resources, to various degrees, but as the number above should suggest, this is not an insignificant amount of resource consumption. There are several problems with this interpretation, the most prominent being that food availability is not the only problem with feeding the world. Most analyst agree that food distribution is the largest impediment. Food produced in the US does not have a clear route to famished peoples, food does not grow everywhere equitably, and the largest producers of food are rarely the most in need. But food also costs energy to produce, and, overwhelmingly, poor nations will be disproportionately impacted by climate change, which means even if there is no chance that food for your pets could have been food for the famished, the carbon-cost of producing pet food will have negative impacts on the developing world.

If you believe any of those numbers. If you don’t, pets are still a problem.

The most common domestic pets, dogs and cats, are rarely native species. They have traveled the world alongside Homo sapiens for thousands of years, sharing our homes, our food, and our diseases. When domestic animals are introduced into a new ecosystem they also introduce the diseases and parasites they’ve acquired from their long travels and close association with humans. Among the diseases that have been transmitted to wild populations by domestic cats are: feline leukemia virus in cougars and bobcats; feline immunodeficiency virus in lions, leopards, and cheetahs; and feline panleukopenia virus in the highly endangered Florida panther population. Again, I’m not picking on cats for any other reason than that there is data available.

But speaking of cats, domestic cats introduced into non-native habitats have had devastating effects on the local ecosystem. Free-ranging domestic cats prey is comprised of 70% small mammals and 20% birds. This adds up to almost 1000 wild animals per cat per year. After habitat destruction, domestic cats are the second leading cause of extinction among wild birds. In one of the most infamous cases, Tibbles, the pet cat of a lighthouse keeper in New Zealand, was reported to have killed the very last Stephens Island Wren (a few more wrens were found in the following years, but the species was already functionally extinct).

All of this leads up to a bigger theme – pets have a real and lasting impact on both social and natural ecosystems, their position in society is problematic, and when talking about living sustainably, the choices we make with regards to our pets matter.

In the TED talk we posted this morning, Hans Rosling talks about where the onus for environmental change rests. Dramatic changes in our lifestyle need to be made among the wealthiest, not the poorest, and one of the most significant changes you can make in your personal life is committing to be a sustainable pet owner.

What are sustainable pets?

The first step in becoming a  sustainable pet owner is asking yourself, “do I really need a pet?” Remember, the lowest environmental impact you can have regarding your pets is none at all. Take the money you’ll save from not owning a pet and donate to local organizations that help reduce feral animal populations. Beyond that, there are three guidelines that will help you define what is and is not a sustainable pet.

1. A sustainable pet minimizes resource consumption.

This includes food, water, and energy. For some reason, in the United States we’ve grown resistant to feeding dogs from the table. Domestic animals, such as dogs, pigs, chickens, and goats, have lived with humans for thousands of years, evolving to eat the food we eat. Pets that can eat table scraps and other human food waste will require less food manufactured specifically for them. Pets that demand large amounts of water, such as fish in aquaria, also consume more resources than needed. So do pets that require demanding electronic devices.

So a sustainable pet has few specialized food needs, which can be supplied locally, and does not require a huge amount of water or electricity for survival.

2. A sustainable pet minimizes environmental damage.

This means that a sustainable pet does not have a negative impact on the environment either as a pet, while being produced, or if it escapes. A tropical fish in a small tank isn’t going to wipe out all your local birds, but tropical fish are often collected live from reefs, which are damaged in the process and have a low survival rate. This also means that exotic pets which have the potential to be invasive, like lion fish, pythons, snakeheads, and yes, even cats, rats, and dogs, if they were to escape, should also be avoided. Pets that require food and materials which have to shipped long distances or produced in environmentally destructive ways, also need to be avoided.

3. A sustainable pet provides a product or service.

This is probably the guideline that will garner the most criticism, but a sustainable pet that also produces means that not only are you minimizing the resources required for that pet, but you are also gaining a benefit that would have to be acquired through other means. This includes pets that produce meat, milk, or eggs, pets who can create rich and fertile compost for your garden (to grow more food), and pets who provide a service to yourself or the ecosystem. And yes, in some cases, companionship is a service.

An example

Sustainable pets is a floating goalpost, which is why the above are guidelines, not rules. What makes good sustainable sense in one situation may be a terrible idea in another. If you’ve been reading the blog, you know that I’ve recently started a small flock of backyard chickens. Chickens make a good choice where I live because: 1. Chickens can eat table and garden scraps, the food they need is local, cheap, and abundant, they have low water demands (which can be met by rainwater in this area) and low energy demands (a small heat lamp as chicks). 2. Chickens have low impacts on the local environment and raising your on chickens bypasses factory farming. Chickens can spread diseases to local birds, though. 3. Chickens provide several products and services. They produce eggs and meat, eat insect larvae (including the invasive Japanese beetle), and generate compost for the garden.

Warning, a bit o’ British humour (and fowl language) NSFGW*

Does this mean I can’t have a pet cat or dog?

No. The above guidelines do not exclude any specific animal. Remember, sustainability is dependent on where you live and what you need. Cats and dogs can be sustainable in the right context. The challenge is to balance your needs as a pet owner with the environmental demands of the animal. Exotic birds and ornamental fish will rarely be sustainable. In some cases it may be impossible to justify any pet at all.

There are good reasons to own pets, and there are bad reasons to own pets. Deciding that a sustainable life means not getting a pet may not be appealing, but sustainable living means that sometimes we have to make sacrifices. Sustainability isn’t always easy, but it is not only a necessity; it is an inevitability in our changing world.


Trotz-Williams LA, & Trees AJ (2003). Systematic review of the distribution of the major vector-borne parasitic infections in dogs and cats in Europe. The Veterinary record, 152 (4), 97-105 PMID: 12572938

Sleeman JM, Keane JM, Johnson JS, Brown RJ, & Woude SV (2001). Feline leukemia virus in a captive bobcat. Journal of wildlife diseases, 37 (1), 194-200 PMID: 11272497

Steven A. Osofsky, Karen J. Hirsch, Evelyn E. Zuckerman and William D. Hardy Jr. “Feline Lentivirus and Feline Oncovirus Status of Free-Ranging Lions (Panthera leo), Leopards (Panthera pardus), and Cheetahs (Acinonyx jubatus) in Botswana: A Regional Perspective” Journal of Zoo and Wildlife Medicine Vol. 27, No. 4 (Dec., 1996), pp. 453-467

Roelke ME, Forrester DJ, Jacobson ER, Kollias GV, Scott FW, Barr MC, Evermann JF, & Pirtle EC (1993). Seroprevalence of infectious disease agents in free-ranging Florida panthers (Felis concolor coryi). Journal of wildlife diseases, 29 (1), 36-49 PMID: 8445789

*Not Suitable for Government Work (unless there’s a shutdown, in which case, go crazy, you’re not getting paid anyway)


Deep-sea biologist, population/conservation geneticist, backyard farm advocate. The deep sea is Earth's last great wilderness.


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