Tag: Prof Andrew Knight

  • How Much Do Vegan Diets Improve the Health of Dogs?

    Pet food consumes at least 9% of all livestock globally, rising to 20% in nations such as the US with high pet ownership. The environmental benefits of vegan pet diets were recently found to be game-changingly large. Most of these relate to dog food. But, can dogs be healthy without consuming meat?

    Dogs are biologically omnivores, and many companies now produce vegan dog food using plant, mineral and synthetic ingredients to supply all necessary nutrients. By 2024, 10 scientific studies had demonstrated good health outcomes in dogs fed vegan or vegetarian diets, and the British Veterinary Association had endorsed nutritionally-sound vegan dog diets. Yet no studies had calculated the size of the health benefits that might occur for average dogs, after controlling for age, sex, neutering status, breed size and exercise level – all factors that can affect dog health.

    In 2024 veterinary Professor Andrew Knight and two colleagues published the first study to control for all of these factors. After analysing health outcomes for 2,536 dogs, including 336 fed a vegan diet for at least one year, they found decreases in the occurrences of seven general indicators of illness. Dogs fed vegan diets were less likely to need medication, medical diets or unusually high numbers of veterinary visits, were more likely to be assessed as healthy by dog owners and their veterinarians, had lower rates of illness, and fewer cases of health disorders when they were unwell. Reductions ranged from 14% – 51% for average dogs, compared to dogs fed conventional meat-based diets. All of these differences were statistically significant, meaning they almost certainly reflected true differences rather than random variation.

    Additionally, the odds of suffering from six specific health disorders fell by 50%-61% compared to dogs fed conventional meat. These included some of the most common health disorders in dogs: problems with body weight, ears, and the musculoskeletal and gastrointestinal system ­- which can cause conditions such as lameness and diarrhoea.

    Among the 22 most common health disorders found in a 2022 study of the same dogs, 11 were most common in dogs fed conventional meat, eight in dogs fed raw meat, and three most common in dogs few vegan diets. 49% of dogs fed conventional meat were unwell, compared to 43% fed raw meat, and 36% fed vegan diets.

    Stated Prof. Knight, “Dogs fed vegan diets clearly had the best health outcomes in this very large-scale study, and these results are consistent with prior studies in this field. Nutritionally-sound vegan diets offer extremely large environmental benefits, so this is very good news for dog owners who want to protect the environment whilst also maximising their dogs’ health. However, care should always be taken to ensure diets are nutritionally-sound, by checking package labelling and purchasing from reputable pet food companies.”

    Contact Information
    Andrew Knight
    Veterinary Professor of Animal Welfare
    andrew.knight@murdoch.edu.au

    SOURCE: Prof. Andrew Knight

  • British Veterinary Association Ends Opposition to Vegan Diets for Dogs

    The British Veterinary Association (BVA) has ended its opposition to (nutritionally-sound) vegan diets for dogs. Until recently, its opposition was regularly reported. However, the BVA also has a corporate partnership with Mars Petcare, which makes large sums from selling meat-based pet foods. Stated Andrew Knight, veterinary Professor of Animal Welfare: “The Mars-BVA partnership represents a significant conflict of interest. Veterinary associations have a responsibility to ensure their positions are evidence-based, up-to-date and not influenced by conflicts of interest.

    Following such critique, in 2023 the BVA ceased its public statements opposing vegan pet food and established a working group to review its position on companion animal diets, including vegan diets.

    And on 24th July 2024, the BVA ended its opposition to (nutritionally-sound) vegan dog diets, publishing an article and policy position on pet diet choices. The new policy confirmed that: “It is possible to feed dogs a plant-based diet…”. It did not attempt to determine the ‘best’ diet for individual pets but rather, “focuses on supporting pet owners to ensure they are meeting their pets’ nutritional needs as well as meeting their own lifestyle choices.”

    Pet guardians have been keen to adopt vegan pet diets. The BVA noted that 42% of companion animal vets reported they had clients who feed meat-free diets. The switch to such diets is being driven by concerns about the health, environmental, and food animal welfare impacts of meat-based diets. Considering pet health, by mid 2024, 10 studies in dogs and three in cats had demonstrated equivalent or superior health outcomes using (nutritionally-sound) vegan or vegetarian diets. These included large-scale studies, studies using veterinary clinical examinations, diagnostic tests and laboratory data, and studies reporting veterinary health assessments, as well as owner opinions (which were recently found to be uninfluenced by diet choice, also increasing confidence in their reliability).

    When considering environmental benefits, the key study in this field recently found that a global transition toward nutritionally-sound vegan diets for the 471 million pet dogs and 373 million pet cats owned worldwide in 2018, would provide major environmental benefits. If all pet dogs were transitioned, it would save more greenhouse gases than produced by the entire UK. If all pet cats were transitioned, sufficient food energy could be saved to feed 70 million people – more the entire UK population. Transitioning pet dogs would allow 450 million people to be fed – greater than the entire EU population. And around seven billion farmed land animals would be spared from slaughter annually, or 9% of the global total, with significantly higher proportions in countries with high pet ownership, such as the UK or US.

    Stated Prof. Knight: “It is commendable that the BVA has finally ended its unscientific opposition to (nutritionally-sound) vegan dog diets and has noted the environmental benefits that plant-based ingredients may provide. It is now up to international veterinary associations to follow suit.” Further information is provided at Prof. Knight’s website.

    Contact Information
    Andrew Knight
    Veterinary Professor of Animal Welfare
    andrew.knight@murdoch.edu.au

    SOURCE: Prof. Andrew Knight

  • New Research Increases Confidence in the Benefits of Vegan Diets for Dogs

    new study has increased confidence in the apparent benefits of vegan diets for dogs. The study reanalysed data within a key 2022 study of 2,536 dogs – the largest published study within this field. That study concluded that the healthiest and least hazardous dog foods were nutritionally-sound vegan diets. However, owner opinions of health were included, which may not always be reliable. For example, owners committed to feeding vegan or meat-based diets might sometimes fail to recognise or report subsequent health problems.

    The new study used additional statistical methods, including machine learning, to analyse owner opinions of health. It found these were minimally affected when vegan diets were fed. Stated Prof. Andrew Knight – lead author of the original study, “I was relieved to see confirmation that feeding vegan diets had minimal impact on owner opinions about health. This increases my confidence in the reliability of the owner opinions we used.”

    The new study focused specifically on subjective owner opinions of health, in contrast to the original study which examined seven general indicators of illness, including more objective data such as the frequency of medication use, therapeutic diet use, and veterinary visits. The original study also analysed the reported assessments of veterinarians concerning dog health, as well the prevalence of 22 of the most common health disorders in dogs. Stated Knight, “The large number of health parameters we studied, and the very large number of dogs included, provide a high degree of confidence in the results.”

    By May 2024 there were 10 studies in dogs, and three in cats, demonstrating equivalent or superior health outcomes when vegan diets are fed, as well as one systematic review covering both species. In April 2024, the longest, most comprehensive peer-reviewed study demonstrated that dogs fed nutritionally-sound vegan diets maintained health outcomes as well as those fed meat. The study comprehensively analysed blood cells and biochemistry, blood nutrient levels, urine, veterinary clinical parameters, and monthly pet owner questionnaires. It studied 15 dogs fed solely vegan diets for an entire year – just under one tenth of an average dog lifespan, or around seven human years. Another 2022 study demonstrated that 1,052 dogs fed vegan diets lived 1.5 years longer, on average, than dogs fed meat. Stated Prof. Knight, “This equates to around an extra decade of life for a human. Additionally, dogs fed vegan diets appear less impacted by certain health problems that impair quality of life. However, it is essential that any diets fed be nutritionally-sound.”

    Prof. Knight also analysed the environmental benefits of vegan pet diets in a major recent study. This demonstrated that if all the world’s pet dogs went vegan, more greenhouse gases than those emitted by the UK would be saved. Knight stated that “Climate change is becoming a major threat to life on Earth. With the livestock sector a leading cause, substantial dietary change is now essential, and that includes pet diets.”

    Contact Information
    Andrew Knight
    Veterinary Professor of Animal Welfare
    andrew.knight@winchester.ac.uk

    SOURCE: Prof. Andrew Knight

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    View the original press release on newswire.com.

  • Tenth Study Demonstrates Good Health in Vegan Dogs

    Tenth Study Demonstrates Good Health in Vegan Dogs

    Although biologically omnivores, dogs are often labelled as carnivores. Almost never are they considered vegetarians. Yet vegan pet foods (excluding any animal products) are increasingly being developed for environmental and animal welfare reasons. And now a study just published in the British Journal of Nutrition has demonstrated good health outcomes in dogs fed vegan diets. Dr Sarah Dodd and other veterinary nutritional specialists from Canada’s Ontario Veterinary College found that 31 dogs fed vegan diets for three months had health outcomes as good as 30 fed meat-based diets.

    The dogs were comprehensively assessed via veterinary examinations, blood and urine tests, and X-rays. Vitamin D plays a key role in regulating bodily calcium levels, and in maintaining good bone health. It is normally sourced from animals, and the effectiveness of vegan vitamin D had been uncertain. However, Dodd’s research group showed that blood levels of vitamin D and calcium did not change in dogs fed entirely vegan diets. X-rays confirmed that bone mineral content and density were unaffected, and other health parameters were also maintained.

    This is the latest among 10 studies that have now confirmed good health outcomes in dogs fed vegan diets. Some are very large-scale studies, following an explosion of recent interest in this field. In 2002, Dodd and her colleagues analysed the lifespans of 1,201 dogs, finding that dogs fed vegan diets lived 1.5 years longer, on average. Said Andrew Knight, a veterinary Professor of Animal Welfare, “That equates to around an extra decade, at the end of a human lifespan. And as well as longer lives, dogs fed vegan diets seem to enjoy better quality of life, because rates of key illnesses impacting life quality, consistently appear lower.” In 2002 Prof. Knight and colleagues also studied health outcomes in 2,536 dogs and concluded that the healthiest and least hazardous diets for dogs were nutritionally sound vegan diets.

    Even cats appear to benefit from vegan diets, provided these are nutritionally-sound. At least three studies have confirmed positive health findings in cats. A 2023 study of 1,369 cats by Knight and colleagues calculated reductions in risks of a broad range of illness indicators, for cats fed vegan diets. Their detailed analysis of feeding behaviour of 2,308 dogs and 1,135 cats also found that average pets appeared to enjoy vegan meals, as much as those based on meat.

    Knight commented that these new studies had opened the door to major environmental benefits offered by vegan pet food. His 2023 study calculated that vegan pet food could save enormous quantities of greenhouse gases, land, and water and that resultant food energy savings could feed billions of additional people globally. Another landmark study also recently identified major climate benefits associated with plant-based diets.

    However, Knight cautioned that, “to safeguard the health of our pets, it is important we feed only commercial vegan pet foods labelled as nutritionally complete, produced by reputable companies with good standards.”

    Contact Information
    Andrew Knight,
    Veterinary Professor of Animal Welfare
    andrew.knight@winchester.ac.uk

  • Diet Choice Could Help Solve the Climate Crisis, Major New Study Finds

    Diet Choice Could Help Solve the Climate Crisis, Major New Study Finds

    In a major new study, prominent scientists from around the world have developed a new strategy for addressing climate change. The study “Proposed solutions to anthropogenic climate change: a systematic literature review and a new way forward,” published in leading scientific journal Heliyon, demonstrates that climate change solutions must include a shift to a more fundamentally plant-based diet and a global phaseout of industrialized animal farming. The authors also recommend the adoption of an “All Life” approach that recognizes the profound interconnectedness of all life on Earth and a global standardization of climate change metrics.

    Solutions to anthropogenic climate change

    Our planet is in a state of emergency and we only have a short window of time (7-8 years) to enact meaningful change to prevent an eventual global climate crisis that will impact each and every one of the Earth’s inhabitants. To achieve this monumental task in such a short space of time, human activities cannot continue on a “business-as-usual” basis. And the data clearly indicate that we will not succeed without changes in the way that we eat and produce food.

    “We must recognize that by solely focusing on reducing greenhouse gas emissions to limit global warming, we are treating the symptom of the cause, and the cause is major global unsustainability. To achieve long-lasting transformative change, which will benefit current and future generations (and save our planet), we need to change our mindset and behavior as individuals, communities, businesses, governments, and global citizens,” says lead author Svetlana V. Feigin, Ph.D.

    “Animal agriculture is not necessary (nor sustainable) to feed the growing global population,” the authors contend. Regarding the phaseout of industrialized animal farming, the authors propose “ending government subsidies for animal-based meat, dairy and eggs, and initiating taxes on such products to account for the wide-ranging externalized costs that are currently passed on to taxpayers, governments, societies and future generations.” Other actions include “more stringent legislation on animal welfare standards and divestment in industrialized animal agriculture.”

    Also in the study, the authors introduce and discuss the concept of an “All Life” approach. An “All Life” approach emphasizes the protection of the “oneness of life” (humans, animals, plants, the entire planet), and emphasizes that our health, and the health of our planet, are intimately intertwined with the health and wellbeing of all living beings. It emphasizes the interdependence and protection of all life forms and shifts away from a human-centric paradigm to an Earth-centric paradigm.

    We are running out of time to alter our current trajectory, and thus to enact meaningful change that will have a profound impact upon the future wellbeing of the planet and all of its inhabitants. Failure to act will ultimately result in a scenario of irreversible climate change, with widespread famine and disease, global devastation, climate refugees, and warfare following resource scarcity.

    Contact Information

    Andrew Knight, Veterinary Professor of Animal Welfare, andrew.knight@winchester.ac.uk

    Svetlana Feigin, Dr drsvetlanafeigin@gmail.com, (+64) 21 1368549 (New Zealand)

  • Could Vegan Pet Food Help Save the Planet?

    Could Vegan Pet Food Help Save the Planet?

    Studies show plant-based diets lower greenhouse gas emissions (GHGs), and use less land and water. Food energy savings mean more people can be fed. This has triggered calls for vegan diets – but not for our pets. Yet a new major study published in leading scientific journal PLOS ONE has demonstrated very large environmental benefits associated with nutritionally-sound vegan diets – for dogs and cats, as well as people.

    After analysing pet food ingredients in detail, Veterinary Professor Andrew Knight calculated that the world’s dogs and cats consume seven billion land animals annually, as well as billions of fish. If all the world’s dogs went vegan, it would save more GHGs than those emitted by the UK, land larger than Mexico, and could feed 450 million additional people – more than the entire EU. If all the world’s cats went vegan, it could feed 70 million additional people – more than the entire UK. And if all the world’s people went vegan, it would save more GHGs than all those emitted by the entire EU, land larger than Russia – the world’s largest country, combined with India, and would feed around 5.3 billion additional people – two thirds of the Earth’s current population.

    Until recently, vegan diets were not seriously considered for dogs and cats – who are biologically omnivores and carnivores respectively. In the last two years however, many new vegan pet foods have been developed by companies using plant-based ingredients supplemented with vitamins, amino acids and minerals, to ensure all necessary nutrients are included. New studies have shown good health and behavioural outcomes for dogs and cats using such diets. There are now 9 such studies in dogs, and 3 in cats. The most recent very large-scale study showed positive health outcomes in vegan cats, following a similar canine study in 2022. These have driven rapid growth with the vegan dog food market valued at USD 14 billion by 2023, and expected to reach USD 26 billion by 2033.

    Said Professor Knight, “This is game-changing. We’ve long known that plant-based diets are better for the planet, but have not seriously considered pet food. However, pet food clearly has profound environmental impacts. Conversely, very large environmental benefits can be achieved by nutritionally-sound vegan pet food. Large-scale studies have also shown that health outcomes for both dogs and cats are as good or better. And studies of feeding behaviour have demonstrated that average dogs and cats enjoy vegan pet foods as much as those made from meat.”

    He concluded: “Pet owners who care about the environment or their animals’ health should consider nutritionally-sound vegan pet food. However, to safeguard health, it is important that people feed only commercial diets labelled as nutritionally complete, produced by reputable companies with good standards.”

    Contact Information
    Andrew Knight
    Veterinary Professor of Animal Welfare
    andrew.knight@winchester.ac.uk

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  • Vegan Cats Challenge Carnivorous Expectations

    Vegan Cats Challenge Carnivorous Expectations

    Cats may not be quite as carnivorous as once thought. Whilst biologically carnivorous, cats are increasingly being fed vegan diets – and thriving! In fact, a ground-breaking new study has just found that cats are healthier, when fed vegan diets. The study, just published in leading scientific journal PLOS ONE, is the largest such study to date. It resulted from an international collaboration led by veterinary Professor Andrew Knight (UK) and co-authored by statisticians Dr Alexander Bauer (Germany) and Hazel Brown (UK). It studied 1,369 cats fed vegan or meat-based pet food, for at least one year. Cats fed vegan diets had better health outcomes for each of seven general health indicators studied.

    Vegan cat health outcomes – Health outcomes in 1,369 cats fed vegan or meat-based diets for at least one year

    Average cats fed vegan diets had a 15% lowered risk of needing medication, and were 7% less likely to visit vets more often, which could indicate illness. Forty two percent of cats fed meat suffered from at least one health disorder, whereas this fell to 37% amongst vegan cats. Of the 22 most common health disorders, 15 were most common in cats fed meat, and seven most common in those fed vegan diets. Although these reductions were not statistically significant, collectively they reveal a strong trend. They also translate into cost savings for pet guardians, which may be considerable over the lifetime of a cat, given the costs of illness and veterinary care. Vegan pet foods also offer significant environmental benefits.

    Stated Andrew Knight, a Veterinary Professor of Animal Welfare and the study leader:
    “For every single general health indicator studied, these cats had better health outcomes when fed vegan diets. This represents a strong and consistent trend. It indicates that pet food manufacturers are now designing and creating vegan pet foods to include all necessary nutrients, but with fewer of the dietary hazards that are prevalent within meat-based pet foods. Cats consuming vegan diets have better health outcomes, as a result.”

    These results concur with those of other, recent studies. In 2021, leading veterinary nutritionist Dr Sarah Dodd and colleagues published a study of 1,026 cats, of whom 187 were fed vegan diets. Cats fed vegan diets were more frequently reported by their guardians to be in very good health. They had more ideal body condition scores, and were less likely to suffer from gastrointestinal and liver disorders, than cats fed meat. No health disorders were more likely, for cats fed vegan diets. These studies are available via www.SustainablePetFood.info > health.

    Prof. Knight stated:
    “This offers exciting potential to improve not only feline health, but also to address the very significant environmental impacts of the livestock sector created through pet food production. However, to safeguard the health of our feline friends, it is important that pet guardians feed only commercial vegan pet foods labelled as nutritionally complete, produced by reputable companies with good standards.”

    www.sustainablepetfood.info
    www.aknight.info/articles/pet-food
    www.aknight.info/vids

    Contact Information
    Andrew Knight
    Veterinary Professor of Animal Welfare
    andrew.knight@winchester.ac.uk