Vegan versus meat-based pet foods: Owner-reported palatability behaviours and implications for canine and feline welfare

Vegan versus meat-based dog food: Guardian-reported health outcomes in 2,536 dogs, after controlling for canine demographic factors

To compare health outcomes between dogs fed meat and vegan diets, we surveyed 2,536 dog guardians who provided data and opinions about dogs fed conventional meat (1,370 = 54 %), raw meat (830 = 33 %) or vegan (336 = 13 %) diets for at least one year. We examined seven general indicators of illness: increased numbers of veterinary visits, medication use, progression onto a therapeutic diet after initial maintenance on a vegan or meat-based diet, reported veterinary assessment of being unwell, reported veterinary assessment and guardian opinion of increased illness severity, and number of health disorders per unwell dog. We also considered the prevalence of 22 specific health disorders, based on reported veterinary assessments. In each dietary group the proportions of dogs considered to have suffered from health disorders were: conventional meat - 49 %, raw meat - 43 % and vegan - 36 %. Probabilities of suffering from a disorder respectively appeared highest in dogs fed conventional meat for 11 disorders, raw meat for eight disorders, and vegan diets for three disorders. We conducted regression analyses to control for differences in medically-relevant canine demographic variables, including age, sex, neutering status, breed size and unusually high exercise levels. Dogs fed vegan diets had the best health outcomes. This trend was clear and consistent, with dogs fed vegan diets usually having substantial and statistically significant decreases in risks of these seven general indicators of illness. These ranged from 14.4 % to 51.3 % compared to dogs fed conventional meat-based diets. For six specific disorders, vegan diets were associated with statistically significant risk reductions of 50 %-61 % compared to dogs fed conventional meat. After pooling our results with related studies published to date, vegan dog food was consistently associated with lowered risks of multiple specific health disorders. No health disorder was consistently more prevalent in dogs fed vegan diets.

The relative benefits for environmental sustainability of vegan diets for dogs, cats and people

Environmental impacts of the livestock sector are proportional to consumption levels. To assess the relative consumption of livestock animals within the diets of dogs, cats and people, this study examined their dietary energy needs within the US in 2020, and globally in 2018. Also studied were US pet food ingredients, and environmental sustainability indicators for plant- and animal-based foods consumed globally. Relative consumptions of average livestock animals were: US: dogs- 17.7%, cats- 2.3%, humans- 80.0%; and globally: dogs- 7.7%, cats- 1.2%, humans- 91.1%. Full transition to nutritionally-sound vegan diets would spare from slaughter the following numbers of terrestrial livestock animals annually (billions): US: dogs- 1.7, cats- 0.2, humans- 7.8, and globally: dogs- 6.0, cats- 0.9, humans- 71.3, as well as billions of aquatic animals in all dietary groups. Very large impact reductions were also associated with land and water use, emissions of greenhouse gases (GHGs), acidifying and eutrophifying gases, and biocide use, in all dietary groups. If implemented globally, nutritionally-sound vegan diets would free up land larger than the following nations: dogs-Saudi Arabia or Mexico, cats-Japan or Germany, humans-Russia-the world's largest country-combined with India. Such diets would save freshwater volumes greater than all renewable freshwater in the following nations: dogs-Denmark, cats-Jordan, humans-Cuba. Such diets would reduce GHGs by amounts greater than all GHG emissions from following nations: dogs-South Africa or the UK, cats-Israel or New Zealand, humans-India or the entire EU. The numbers of additional people who could be fed using food energy savings associated with vegan diets exceeded the 2018 human populations of the following nations: dogs-the entire European Union, cats-France or the UK, humans-every single nation or collective region on Earth, as defined by the World Bank. All of these estimates are conservative.

Vegan versus meat-based cat food: Guardian-reported health outcomes in 1,369 cats, after controlling for feline demographic factors

Increasing concerns about environmental sustainability, farmed animal welfare and competition for traditional protein sources, are driving considerable development of alternative pet foods. These include raw meat diets, in vitro meat products, and diets based on novel protein sources including terrestrial plants, insects, yeast, fungi and potentially seaweed. To study health outcomes in cats fed vegan diets compared to those fed meat, we surveyed 1,418 cat guardians, asking about one cat living with them, for at least one year. Among 1,380 respondents involved in cat diet decision-making, health and nutrition was the factor considered most important. 1,369 respondents provided information relating to a single cat fed a meat-based (1,242-91%) or vegan (127-9%) diet for at least a year. We examined seven general indicators of illness. After controlling for age, sex, neutering status and primary location via regression models, the following risk reductions were associated with a vegan diet for average cats: increased veterinary visits- 7.3% reduction, medication use- 14.9% reduction, progression onto therapeutic diet- 54.7% reduction, reported veterinary assessment of being unwell- 3.6% reduction, reported veterinary assessment of more severe illness- 7.6% reduction, guardian opinion of more severe illness- 22.8% reduction. Additionally, the number of health disorders per unwell cat decreased by 15.5%. No reductions were statistically significant. We also examined the prevalence of 22 specific health disorders, using reported veterinary assessments. Forty two percent of cats fed meat, and 37% of those fed vegan diets suffered from at least one disorder. Of these 22 disorders, 15 were most common in cats fed meat, and seven in cats fed vegan diets. Only one difference was statistically significant. Considering these results overall, cats fed vegan diets tended to be healthier than cats fed meat-based diets. This trend was clear and consistent. These results largely concur with previous, similar studies.

Effects of extruded pet foods containing dried yeast (Saccharomyces cerevisiae) on palatability, nutrient digestibility, and fecal quality in dogs and cats

Global protein shortages and sustainability concerns have increased consumer demand for non-animal-derived protein. Dried whole-cell yeast (Saccharomyces cerevisiae) may be a suitable alternative to rendered protein meals in pet foods. The objective of this study was to investigate the effects of dried yeast in dog and cat foods on indicators that pet parents typically use to evaluate the suitability of a food for their pet. For this evaluation, two dog and two cat dry extruded diets were formulated. For each species, the test diet contained 10% dried yeast (Yeast) and the control diet was devoid of yeast (Control). Palatability, apparent total tract nutrient digestibility, and fecal quality of the foods were assessed in dogs and cats. Urine pH and specific gravity were measured in cats as indicators of urinary tract health. In dogs, the Yeast diet showed equivalent or better palatability compared to the Control diet based on total food consumption (P = 0.06), average daily consumption (day 1, P = 0.10; day 2, P = 0.54), and first choice preference over 2 consecutive days (P = 0.005). Cats showed a strong preference for the Yeast diet with more than double the consumption during the 2-d test period (P = 0.001). More cats showed a first-choice preference for the Yeast diet (24 vs. 16), but the difference was not statistically significant (P = 0.21). There were no significant differences in stool quality or nutrient digestibility when fed Yeast vs. Control diets to the dogs and cats (P > 0.05). All cats produced urine with pH and specific gravity values within the normal range, though specific gravity was lower in the Control group (P = 0.003). This study provides support for the acceptability and digestibility of dog and cat diets containing dried yeast as an alternative protein source.

Forty-five years of research on vegetarianism and veganism: A systematic and comprehensive literature review of quantitative studies

Meat production and consumption are sources of animal cruelty, responsible for several environmental problems and human health diseases, and contribute to social inequality. Vegetarianism and veganism (VEG) are two alternatives that align with calls for a transition to more ethical, sustainable, and healthier lifestyles. Following the PRISMA guidelines, we conducted a systematic literature review of 307 quantitative studies on VEG (from 1978 to 2023), collected from the Web of Science in the categories of psychology, behavioral science, social science, and consumer behavior. For a holistic view of the literature and to capture its multiple angles, we articulated our objectives by responding to the variables of "WHEN," "WHERE," "WHO," "WHAT," "WHY," "WHICH," and "HOW" (6W1H) regarding the VEG research. Our review highlighted that quantitative research on VEG has experienced exponential growth with an unbalanced geographical focus, accompanied by an increasing richness but also great complexity in the understating of the VEG phenomenon. The systematic literature review found different approaches from which the authors studied VEG while identifying methodological limitations. Additionally, our research provided a systematic view of factors studied on VEG and the variables associated with VEG-related behavior change. Accordingly, this study contributes to the literature in the field of VEG by mapping the most recent trends and gaps in research, clarifying existing findings, and suggesting directions for future research.

Vegan versus meat-based dog food: Guardian-reported indicators of health

Alternative pet foods may offer benefits concerning environmental sustainability and the welfare of animals processed into pet foods. However, some worry these may compromise the welfare of pets. We asked 2,639 dog guardians about one dog living with them, for at least one year. Among 2,596 involved in pet diet decision-making, pet health was a key factor when choosing diets. 2,536 provided information relating to a single dog, fed a conventional meat (1,370 = 54%), raw meat (830 = 33%) or vegan (336 = 13%) diet for at least one year. We examined seven general indicators of ill health: unusual numbers of veterinary visits, medication use, progression onto a therapeutic diet after initial maintenance on a vegan or meat-based diet, guardian opinion and predicted veterinary opinion of health status, percentage of unwell dogs and number of health disorders per unwell dog. Dogs fed conventional diets appeared to fare worse than those fed either of the other two diets. Dogs fed raw meat appeared to fare marginally better than those fed vegan diets. However, there were statistically significant differences in average ages. Dogs fed raw meat were younger, which has been demonstrated to be associated with improved health outcomes. Additionally, non-health related factors may have improved apparent outcomes for dogs fed raw meat, for three of seven general health indicators. We also considered the prevalence of 22 specific health disorders, based on predicted veterinary assessments. Percentages of dogs in each dietary group considered to have suffered from health disorders were 49% (conventional meat), 43% (raw meat) and 36% (vegan). Significant evidence indicates that raw meat diets are often associated with dietary hazards, including nutritional deficiencies and imbalances, and pathogens. Accordingly, the pooled evidence to date indicates that the healthiest and least hazardous dietary choices for dogs, are nutritionally sound vegan diets.

It Keeps the Good Boy Healthy from Nose to Tail: Understanding Pet Food Attribute Preferences of US Consumers

The study provides insights for marketing managers in specialized pet supplies retailers, as well as for vets and animal welfare organizations. This study proposes a model that investigates the importance pet owners place on convenience, natural ingredients, and value and health claims as product attributes. For this purpose, an online survey with a sample size of 206 pet-owning US residents was conducted. Partial least squares structural equation modelling shows that pet food purchase involvement positively impacts subjective and objective knowledge about pet food. Subjective knowledge appears to be the strongest factor impacting the importance consumers place on all three attributes. This is followed by objective knowledge. Socio-demographic factors such as gender, age, income, and education appear to have a limited impact as predictors for the importance consumers place on the product attributes.

Nitrogen output in the urban environment using a vegetarian canine diet

Pet owners are increasingly concerned about the links between health status, animal welfare, environmental impacts, climate change and consumption of animal products. Accordingly, many owners are increasingly interested in vegetarian diets for themselves and their companion animals. However, such diets should be investigated nutritionally regards digestibility as well as on fecal quality and nitrogen output. In light of this trend, six Beagle dogs were included in a cross-over experimental design and offered a vegetarian diet containing wheat gluten (8.81%), rice protein (8.81%) and sunflower oil (6.84%) or an meat-based diet containing poultry meal (19.5%) and poultry fat (5.23%). The dogs received extruded complete diets for 12 days (adaptation and collection period, each 6 days). The dogs fed both diets showed a high and identical palatability (scoring of food intake) of the experimental diets. No significant differences occurred regarding digestibility of organic matter, crude protein and crude fat between vegetarian and meat-based diets. However, dogs fed the meat-based diet had higher (p < 0.05) nitrogen-free extract digestibility (89.5%) compared to those fed the vegetarian diet (88.6%). The amount of nitrogen excreted in feces (g)/kg BW^0.75 was slightly, but not significantly, higher for dogs fed the vegetarian diet compared to those fed the meat-based diet (0.88 vs 0.79). The fecal consistency scores were considered to be within an acceptable range (well formed and firm). The mass of the feces between both groups were similar (62.9 g wet feces/100 g dry matter food) for vegetarian and meat-based diets. Additionally, the fecal dry matter content was comparable between both groups (29.0% and 29.6% for vegetarian and meat-based diets, respectively). In conclusion, the results of this study appear to indicate that virtually the only significant difference between the two diets was lower nitrogen-free extract digestibility in the vegetarian diet. However, the vegetarian diet did not result in a significant difference in amount of nitrogen excreted in feces.