When it comes to dog food there are lots of differing opinions on what’s best. From home prepared, home cooked, kibble (meat based, insect protein, vegan, vegetarian), vegan dog food and many more there are always differing opinions as to what is best. But that is beyond the scope of this article.

Today, we are going to investigate which is most environmentally friendly.

Our environment 

It must be noted that we should all be taking steps towards protecting our environment. And, as the pet population is expanding, we need a way to feed them in a way that does not have a significant impact on the environment, agricultural land, and global warming.

A study showed that an area double the size of the UK is used to produce dry pet food for cats and dogs each year. Analysis of the carbon footprint of pet food production also revealed that the industry emits more greenhouse gasses each year than countries such as Mozambique. Clearly this is something we as consumers, and larger companies producing foods should be aware of and make conscious efforts to improve. 


Much of the pet food industry for the UK market uses meat that is ‘human grade’ (see later what I mean by this term) but is just not desirable for people in the UK to eat – such as off cuts, offal and organs. These are very nutritious parts of the animal. They would otherwise be binned and go to waste if not used as pet food. One would argue that this use reduces unnecessary waste of animal products while still using meat products that are extremely nutritious to our dogs. 


By-products are sustainable and healthy for animals to consume. A sensible way to feed our pets meat-based diets with minimal footprint is to use every part of the animals we slaughter for human food, including organs.

These by-products, which do not include hair, horns, teeth or intestinal contents, often collectively termed “by-products,” can be very good-quality sources of nutrients that pets enjoy.

However, we still have a way to go with Dr Peter Alexander from the School of GeoSciences and Global Academy of Agriculture and Food Security saying, ‘Even accounting for the use of by-products in pet foods, the feeding of companion animals plays a role in environmental change.’

Meat based foods using ‘human grade’ as a pull

All dog food must derive from ‘human grade’ in the UK. Although the terminology can get a little confusing so I will try to expand. They do have ‘animal grade’ meats in the US which is where confusion comes in.

There have been “human-grade” claims on some pet foods for a few years; with some companies using it as a marketing tool to make people think the meat used is better quality or subject to stricter testing. This term has no definition in any animal feed regulations. For example, in the UK we cannot give humans certain categories; nor can we use that as part of pet foods either.

Category 3 ABPs are classed as low risk and are more applicable to animal by-products; which are really great for animal feeds as detailed above; they are highly nutritious and just not that appealing to the human market.

To make pet food you can only use ‘human grade’ (using the term we are just trying to describe the fact that the meat IS okay for human consumption). But they use meats that were unwanted; such as slaughterhouse material that was passed fit for humans to eat but is unwanted for commercial reasons.

When looking into the ingredients list as owners we may prefer to see certain things on there, as they are more appealing to us. This is not necessarily synonymous with superior nutrition.

One article concluded

“In summary, while we may feel better about feeding a diet full of great-sounding ingredients, these diets are usually similar or even potentially less nutritious than diets containing less appealing (to people) ingredients. There is no way to determine diet quality from the label or the ingredient list.”  

Vegan diets

One study concluded that around 49 million hectares of agricultural land – roughly twice the size of the UK – are used annually to make dry food for cats and dogs; which accounts for 95 percent of pet food sales. Furthermore, annual greenhouse gas emissions were found to be 106 million tonnes of carbon dioxide; a country producing the same levels would be the world’s sixtieth highest emitter. 

However, it should be noted that this study found that around half of dry food is already made up of crop plants – such as maize, rice or wheat. So cannot be fully attributed to the production of the meat. 

That being said, there is no doubt that to feed humans and dogs alike meat products, there will be some impact on the environment. In 2018, research found that meat and egg consumption contribute the largest share of food supply emissions in the EU; averaging 56% across all EU countries.

Livestock activities contribute an estimated 18 percent to total anthropogenic (chiefly of pollution or environmental change originating in human activity) greenhouse gas emissions from the five major sectors for greenhouse gas reporting; energy, industry, waste, land use, land use change and forestry (LULUCF) and agriculture. Considering the last two sectors only, livestock’s share is over 50 percent. For the agriculture sector alone, livestock constitute nearly 80 percent of all emissions.

One study believed that dietary change could deliver environmental benefits

They believe that moving from current diets to a diet that excludes animal products has transformative potential; reducing food’s land, reduction in arable land; reduction in food’s greenhouse gas emissions and reduction in acidification and eutrophication.

The theory is that rather than growing crops to feed the animal to feed the human (or pet) you could just grow the crop to feed the human.

That being said, there are also some negatives to the increased demand for vegan products

Global production of soya beans and palm oils has doubled over the past 20 years and continues to rise. The two account for 90 percent of global vegetable oil production. And they are used in processed foods, animal feed, and non-food products. Furthermore, most popular plant-based proteins, including chickpeas, lentils, and chia seeds, are also usually flown thousands of miles which can add to the issues.  

Additionally, there are other points to consider when thinking about crops that can drive up the environmental impact. Artificial fertilisers, for example, account for at least 3% of global greenhouse gas emissions. The production of synthetic fertiliser emits carbon dioxide (CO2) and methane into the atmosphere; while their use on fields releases nitrous oxide, another potent greenhouse gas.

Agricultural practices such as the tilling of fields (breaking up and stirring soil) also release large volumes of greenhouse gases into the atmosphere and help to speed up erosion.

These all combine to differing degrees depending on the crop. But there are clearly some plant-based foods that have a disproportionate impact on the environment.


This is where, I am afraid, I can’t give a straight answer. As with many things in science it is a battle of weighing up pros and cons and looking at things individually.

Firstly, I cannot say that one meat-based food is better or worse than a plant-based food. This is because there are so many factors that influence this! Where do they source their meat from? What plant-based proteins are they using? What is the company’s sustainability policy and how do they ship and manufacture their product?

As you can see from above discussion, when it comes to the environment, and that is what I am focusing on in this article, although of course there are MANY other factors that could be drawn into this debate (I just don’t have the word count to factor all these points in), then you can see that there are pros and cons to the environmental impact with both kinds of farming. Ultimately owning a pet is likely to contribute to some kind of carbon footprint. So it’s up to us to make choices to the best of our ability to limit that.

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