The carbon footprint of the animals under our care

The animals that UK veterinary surgeons have under their care, as defined by the RCVS Code of Profes­sional Conduct, have significant collective environ­mental impact. Entrusted with the healthcare of domestic animals and as advisors on animal husbandry and manage­ment, veterinary professionals have enormous potential to influence the mitigation of these environmental impacts. Food animals – in particular beef, dairy and poultry – have a very significant carbon footprint, and the relatively small number of vets working with these species means that each of us has the potential to be highly effective when we choose to advise our clients on ways to lower that environ­mental impact. The purpose of this article is to try to quan­tify the carbon footprint of all domestic species in the UK and to give a sense of the scale of the influence we have as veterinary professionals.

We live in an age where there is continuous debate about the state of the environment. The news cycle is full of sto­ries about greenhouse gases (GHGs), plastics, pollution, extreme weather events, protests, species extinctions, energy crises, droughts, flooding and food migration. The scientific consensus is overwhelmingly that the world’s climate is changing, that we are fast losing biodiversity and that human activity is a significant factor in these changes. The fear is that we are rapidly approaching some tipping points beyond which we will not be able to ensure our long-term survival. These are precarious times.

Vets are a highly trusted profession (Robinson et al., 2019), and a British Veterinary Association Voice of the Vet­erinary Profession survey in 2019 showed that 89 percent of UK vets want to play a more active role in the sustainability agenda: Vet Sustain was formed in 2019 partly in response to this, to provide resources and support for those vets and vet nurses who want to “drive change towards a sustaina­ble future”.

There has been a great deal of discussion about the environmental impact of our veterinary activities and of the clinics in which we work: this article takes a look at the car­bon footprint of the animals that we treat, and reviews the numbers of vets that work in each sector. From this infor­mation we can quantify the combined carbon footprint of all the animals that each of us have “under our care”. It gives a sense of the potential scale of our influence.

Data

Agriculture and food production is estimated to be responsi­ble for 26 percent of the total global GHGs produced (Poore and Nemecek, 2018). A third of this is from livestock and fisheries, and a further quarter from land use for human and animal food (Ritchie and Roser, 2020).

It is relatively straightforward to gather accurate data on animal populations and food production, but the issue of the carbon footprint of a kilo of beef, an egg or a litre of milk, for example, is more challenging. Different sources quote figures that vary significantly, and at best these will only be estimates and averages of different animal management sys­tems. The intention here is not so much to produce definitive figures, but to give us a sense of the scale of our potential to improve the situation.

The environmental issues surrounding the UK’s vet­erinary species include the emissions of carbon dioxide, methane and nitrous oxide and their impact on carbon sequestration, biodiversity and water and soil health. Any attempt to be fully comprehensive risks becoming over­whelmed in the detail of the complex and often contradic­tory elements involved.

This article uses the unit of carbon dioxide equivalent (CO₂e) for the key metric of carbon footprint of each unit of animal food produced. The unit of CO₂e has its weak­nesses, but since this article is primarily to give a sense of scale, it has the benefit of simplicity and uniformity across the species.

The combined carbon footprint of the UK’s veterinary species

The “big three” species responsible for the highest annual carbon footprint in the UK are dairy cattle (32 percent of the animal total), beef cattle (27 percent of the animal total) and poultry meat and egg production (17 percent of the animal total; Table 1).

For meat producing species, data was taken from slaughter numbers, average carcass weight and kill out percentage (Defra, 2020a, 2020b) to give total annual meat production, and Defra figures for kg CO₂e per unit of pro­duction were used to give a total annual figure for each species. Industry data is also available for egg and milk production. For cats and dogs, data from Okin (2017) was used as a base line, using average pet body weight, energy requirement/kg, pet food ingredients, pet food purchasing patterns, food conversion efficiency and environmental impact of faeces. These figures were then adjusted for the UK pet population using PDSA data (PDSA, 2020).

The number of UK vets working with each species

The most accurate data available is from the 2019 RCVS Survey of the Profession (Robinson et al., 2019), where vets were asked to quantify what percentage of their time they spent working with each species. The response rate was 42 percent. If the answers were representative of the rest of the profession, we can estimate the number of full-time veterinary equivalents (FTVEs) per species (Table 2). The profession is numerically dominated by dog, cat and equine vets. The numbers of FTVE vets working with the species with the highest carbon footprints (dairy, beef and poultry) is much smaller.

The combined carbon footprint of all animals under the care of each vet, per year, by species

Dividing the total carbon footprint of the species by the number of FTVE vets treating them gives an idea of the car­bon footprint of all the animals under the care of each vet in the sector (Table 3). This can be seen as the potential envi­ronmental influence of each of those vets when advising their clients. For perspective, the average UK person cur­rently has an annual carbon footprint of around 15 tonnes of CO₂e (Mike Berners-Lee, 2010).

So, what can I do?

Reduction in food waste and widespread adoption of a plant-rich diet may be by far the two biggest single opportunities to reduce global GHG emis­sions from agriculture (Project Drawdown, 2021); however, veterinary surgeons are uniquely placed at the interface between the animal world, the environment and the needs of humans and give advice to clients on matters relating to animal health, welfare and, for food animals, production efficiency on a daily basis. Every aspect of every animal management system has environmental consequences, whether in the form of pet diets, livestock housing and nutrition, animal breeding, the way we run our clinics or a multitude of other factors. And when the scale of our influence is large, small percent­age reductions in footprint have the potential for massive impact in our fight to conserve and protect the ecosystem in which we live.

Further work is needed to quantify with any precision the varying footprint of different systems of animal manage­ment, but we already know enough to give general practi­cal advice. Each of us now needs to take the time to get our knowledge up to speed so that we can confidently give very specific practical advice to farmers and animal owners on reducing the impact of the animals they keep. In addition to all the steps we can take in our own clinics, these are just some of the areas where we can make a difference in our contacts with pet and horse owners, farmers, nutritionists, breeding advisors and others:

• Recommend pet diets with lower environmental impact ingredients and packaging. We should con­tinue to explore novel dietary protein sources and, health and hygiene permitting, consider whether some of the estimated 16 percent of food that is wasted in our homes (Wrap, 2020) could end up in our pets instead
• Choose the toys and accessories we recommend carefully, whether purchased from us or elsewhere
• Optimise animal health: reductions of 7 to 25 percent in GHG emissions from cattle have been associated with control of endemic diseases such as Johne’s, salmonella, BVD, infertility, fluke, IBR, lameness and mastitis (ADAS, 2015)
• Implement integrated parasite management on farms and encourage our pet owners to start testing for parasites before we hand out packs of medication
• Advise on ruminant diets: cattle fed maize silage rather than grass silage and sheep fed on higher sugar grass produce lower amounts of methane (Defra, 2010). There appears to be a direct relation­ship between dry matter content of ruminant diets and the methane produced (SRUC, 2015). Some feed supplements have been shown to reduce methane production by 50 percent or more (All About Feed, 2018; Kinley, 2018)
• Management of ruminant and equine manure: this can be a significant source of GHGs, whereas anaerobic digestion of animal manure, crops and crop by-products can be used to generate electricity
• Identify on-farm opportunities to restore soil carbon, build hedgerows, plant trees and wild flower meadows, protect valuable wetlands and peatland, and use biomaterials for construction
• Encourage farmers in their efforts to reduce energy use on farms and support efforts to reduce long distance transport of animals for sale or for slaughter, not just for welfare reasons but also for the environment
• For all species, continue to work with animal owners to refine and reduce our use of antibiotics

We live in a time of unprecedented environmental threat. If our veterinary advice continuously prioritises reducing the environmental impact of the animals we look after in addition to all the more traditional considerations, we will be well on the way to fulfilling our ambition to “play a more active role in the sustainability agenda” (Robinson et al., 2019).