As an introduction to the much-anticipated new book by our colleague and animal nutritionist, Diana Laverdure-Dunetz and myself The Plant-Based Diet for Dogs, Beans Over Bones™, to be published by DogWise Publishing in late 2022, we thought a comparison of two relevant studies about commercially formulated pet food diets would be useful.
Study: “Using a next-generation sequencing approach to DNA metabarcoding for identification of adulteration and potential sources of mercury in commercial cat and dog foods”, Dunham-Cheatham, S. et al., University of Nevada – Reno, 2021.
Analyzed at least 50 commercial pet food samples of DNA for adulteration.
Dr. Dunham-Cheatham was quoted in Nevada Today about this adulterated food study:
“The researchers used DNA in the pet food to test whether actual ingredients matched package labels and suggest that pet food package labeling should be read with caution, as many ingredient labels are not accurate.
‘Every sample we looked at had some inaccuracy, based on our results, some more egregious than others. These are highlighted in the paper,” Dunham-Cheatham said. “We looked at at least 50 samples, of the 90 we analyzed for DNA, for this particular analysis. We weren’t able to definitively answer how many had inaccurate labels due to some limitations of the DNA analysis. As for the DNA results, generically speaking, we found that many of the pet food products were comprised of low-value ingredients, such as chicken, and that products claiming to be made from high-value ingredients, such as fish and novelty proteins, typically contained more low-value ingredients than high-value ingredients.’”
Similar Study: “A Comparison of Key Essential Nutrients in Commercial Plant-Based Pet Foods Sold in Canada to American and European Canine and Feline Dietary Recommendations”, Dodd, S.*, et al., University of Guelph, 2021.
Analyzed 26 commercial plant-based pet foods.
“Cholecalciferol (vitamin D3), found predominantly in animal tissues…Cholecalciferol has been detected in lichen species, which may serve as a source of dietary vitamin D3 in plant-based pet foods.
Concerningly, there was great discrepancy in this study between the labelled source of vitamin D and the type of vitamin D measured. Though twelve of the diets included a vitamin D2 supplement in their ingredient list, only five were found to contain vitamin D2. Two also contained vitamin D3, which was not listed in the ingredients. In those diets, no vitamin D3-rich ingredients (animal or lichen) or vitamin D3 supplements were included in the ingredient list. Cross-contamination could be possible if animal-based diets had been manufactured in the same facility, but this would be insufficient to explain the concentrations of vitamin D3 in those diets, as they contained the full recommended quantity.”
Why did we choose these two studies to compare?
We knew if we focused solely on vegan diets for companion dogs that some readers might use it to confirm their beliefs against vegan diets. We wanted to demonstrate that while vegan diets might come under intense scrutiny, other diets deserve the same amount of scrutiny.
The authors of the plant-based food study for dogs and cats noted in the conclusion, “The findings of the present study suggest that formulation of plant-based foods meeting all nutrient requirements of dogs and cats for all life stages are possible, though current industry practices sometimes fall short of published nutritional recommendations.”
Note the word “sometimes”. They are not discounting the possibility. They are simply saying these diets may need some re-formulations. Throughout this research paper, the researchers discuss when the foods matched, exceeded, or were below recommended minimums.
We had a choice of studies analyzing vegan diets for dogs and cats, but chose this one specifically due to the lack of bias compared to other studies, and because of the breadth of work these researchers, primarily at the University of Guelph, have completed recently. For instance, they are looking at black soldier fly larvae meal as a protein alternative for all types of animals and have experimented with camelina oil as an alternative to other plant-based oils for dogs.
As Anna K. Shoveller, Ph.D. and her colleagues from around the globe stated in an editorial, “With a growing global human population and increased demand for food, there is a need to identify novel or alternative food ingredients and processes for pet foods that increase nutrient availability.”
Bear in Mind
Bear in mind that the researchers are not endorsing another type of pet food or ignoring other industry issues. Since 2018, countless recalls have occurred across several pet food brands in both kibble and canned formulations due to elevated vitamin D levels. Salmonella and Listeria spp. contamination has also been a recent issue in both human and pet foods. Thus, we encourage you to do a simple web search and also set an alert for pet food recalls in case your pet food of choice is recalled, even voluntarily.
One friend and colleague of Hemopet and Jean Dodds’ is Dr. Karen Becker. In following her writings, she is not in favor of vegan diets for dogs (or cats for that matter) and cites, “Dogs evolved to eat very high moisture diets containing large amounts of clean, unheated fat and animal protein, moderate roughage (fiber) and low/no starch.” She often suggests raw or lightly-cooked food for companion dogs.
One of her biggest concerns with vegan diets and kibble is the amount of synthetic supplements added to highly-processed foods to meet Association of American Feed Control Officials (AAFCO) standards.
However, she recognizes the errant problems that can occur with commercial raw pet foods. In an earlier article in Whole Dog Journal from 2015, Dr. Becker, Mary Straus, and Steve Brown provided warnings such as:
“In every recipe we’ve analyzed, there is no need to add a copper supplement to a recipe with beef liver, which is rich in copper (see Table III). In many cases, adding a copper supplement to a recipe that includes beef liver causes the diet to exceed the European legal limit for copper in dog food.
Why do companies add copper to diets containing beef liver? Because it’s easier and less expensive for a manufacturer to use just one supplement mix than to have various mixes for different products. They buy in greater volumes and therefore get lower costs. But in our opinion, there is no good reason for the larger raw diet manufacturers to use the same supplement mix for all of their products.”
Overall, we like gently processed/lightly cooked properly balanced grain-free foods for companion dogs or cats. Remember that dogs have evolved from their wolf ancestors to be obligate omnivores, whereas cats remain as classical carnivores.
We support appropriately balanced raw diets.
We support appropriately balanced vegan diets. Here’s why.
#1. We wholeheartedly agree with the statement that the pet food industry as a whole needs to start looking at alternative food sources and processes for pet foods for sustainability purposes.
#2. Some companion pets have food sensitivities and intolerances to several proteins that make it necessary for parents to either rotate with a vegan meal or go completely vegan.
However, we recognize that sometimes budget, pet sensitivities to certain ingredients, or lifestyle does not allow this approach for pet companion parents.
What We Would Like to See…
There’s more, but here’s a start:
#1. AAFCO standards need to be updated.
#2. More research!
#3. Research needs to turn into development and implementation.
#4. Every companion pet food should be subjected to testing and controlled feeding trials before entering the marketplace.
#5. The industry needs at least to start testing pet food samples regularly to avoid cross-contamination and adulteration, as well as for potential vitamin or mineral toxicities or deficiencies.
#6. The presumptions and prejudices need to stop.
Are you wondering about our practices?
The majority of our dogs here consume meat-based diets. However, some of our dogs are on vegetarian diets. Why? Because based on their NutriScan Food Sensitivity and Intolerance results, they react to several meat and grain proteins.
What we want you to do is do what is best for your pets. As well, please be open to new ideas regarding your companion pet’s diet and not just dismiss them. Let’s let research do its job and help us find available, nutrient-packed alternative food sources for companion pets.
*Sarah Dodd of University of Guelph, Jean Dodds’ alma mater (OVC ’64), but not W. Jean Dodds of Hemopet.
Becker, Karen. “Ignore This ‘Expert’ Advice for a Healthier Gut.” Healthy Pets, Mercola.com, 20 Dec. 2021, https://healthypets.mercola.com/sites/healthypets/archive/2021/12/20/how-to-improve-gut-health-in-dogs.aspx.
Becker, Karen. “Plant-Based Dog Food: Responsible or Reckless?” Healthy Pets, Mercola.com, 7 Mar. 2021, https://healthypets.mercola.com/sites/healthypets/archive/2021/03/07/is-plant-based-dog-food-good-for-dogs.aspx.
Dodd, Sarah A., et al. “A Comparison of Key Essential Nutrients in Commercial Plant-Based Pet Foods Sold in Canada to American and European Canine and Feline Dietary Recommendations.” Animals, vol. 11, no. 8, 2021, https://doi.org/10.3390/ani11082348.
Dunham-Cheatham, Sarrah M., et al. “Using a next-Generation Sequencing Approach to DNA Metabarcoding for Identification of Adulteration and Potential Sources of Mercury in Commercial Cat and Dog Foods.” Science of The Total Environment, vol. 778, 15 July 2021, https://doi.org/10.1016/j.scitotenv.2021.146102.
Shoveller, Anna K., et al. “Editorial: Nutrition and Management of Animals We Keep as Companions.” Frontiers in Veterinary Science, 28 Sept. 2021, https://doi.org/10.3389/fvets.2021.748776.
Straus, Mary. “The State of the Commercial Raw Diet Industry.” Whole Dog Journal, 5 Jan. 2021, https://www.whole-dog-journal.com/food/the-state-of-the-commercial-raw-diet-industry/.
Wolterbeek, Mike. Mercury Levels in Pet Food Cause for Concern, Fish-Based Foods Main Culprit. Nevada Today, 29 Apr. 2021, https://www.unr.edu/nevada-today/news/2021/mercury-in-pet-food.