Vegan versus meat-based pet food

: health, behavioural and environmental implications

Abstract

The environmental impacts created by the livestock sector are globally significant. These include land and water use, fossil fuel consumption, greenhouse gas production, pesticide and fertilizer use, and biodiversity reductions. The consumption of livestock by the pet food sector is large and growing with increasing pet ownership globally. However, alternative pet foods based on novel protein sources, such as plants and seaweed, insects, yeast, fungi and laboratory grown meat, are rapidly developing. Among these, vegan pet foods are most developed. These aim to use plant, mineral and synthetic sources to supply all nutrients required by dogs and cats. My first major publication in this field (2016) reviewed and extended existing evidence concerning the nutritional soundness of vegan pet foods, and the health outcomes of dogs and cats maintained on vegan diets. Next, in 2020 I surveyed 29 pet food manufacturers to determine whether and how nutritional soundness and quality control of vegan or vegetarian pet foods differed from meat-based diets. I also surveyed 4,060 dog or cat guardians to investigate determinants of pet food purchasing decisions, as well as health, behavioural and other outcomes using different diets. The resultant studies included within this thesis examined the nutritional soundness and palatability of vegan dog and cat food, and the health outcomes of animals maintained on these diets. These and related studies have indicated that the healthiest and least hazardous pet foods are nutritionally sound vegan diets. Detailed analysis of feeding behaviour has indicated that vegan diets are, on average, as palatable as meat-based diets, to dogs and cats fed each diet type. And manufacturers of vegan or vegetarian pet foods normally appear to adhere to quality control standards at least as good as those used in the creation of conventional diets. These studies added to a growing body of evidence described within my 2022 – 2023 Veterinary Times letters briefly summarising extant studies evaluating dog and cat health respectively. The final study included within this thesis examined the implications for environmental sustainability of vegan companion animal diets, comparing potential benefits to those offered by human consumption of vegan diets. This added to early publications (2013 & 2018) exploring the environmental and other impacts of the livestock sector. Collectively considered, the environmental and animal welfare benefits of nutritionally-sound vegan dog and cat diets are profound. These factors are already driving a rapid expansion of the vegan pet food sector, which is expected to accelerate as societal concerns about environmental sustainability and animal welfare increase in prominence.

Date of Award	19 Jan 2024
Original language	English
Awarding Institution	University of Winchester
Supervisor	Lisa Riley (Supervisor), Simon Jobson (Supervisor) & Hazel J Brown (Supervisor)