Over the last decade, the pet food industry has seen a surge in "grain-free" diets marketed as healthier alternatives for dogs. Often replacing traditional grains with legumes and pulses like peas, lentils, and chickpeas, these formulations have sparked both consumer enthusiasm and scientific scrutiny. Peas, in particular, are frequently used in grain-free recipes due to their protein content, affordability, and fibre.
But as the popularity of these diets has grown, so too have concerns about their long-term health effects. In August 2021, researchers from Tufts University published a pivotal study indicating that peas may be a leading ingredient associated with a rise in diet-associated canine dilated cardiomyopathy (DCM), a serious and potentially fatal heart condition (1).
In this blog, we explore the role of peas in dog food, the potential risks associated with high legume diets, and how a supplement like CaniNectar could play a supportive role in maintaining gut health amidst dietary changes.
The Appeal and Complexity of Peas in Dog Food
Green peas — including snow peas, sugar snap peas, and garden peas — are generally safe in small quantities. Rich in antioxidants like vitamin A, lutein, and polyphenols, peas offer potential benefits for eye, heart, and skin health. Pet owners often offer fresh or frozen peas as treats, and many commercial foods include them as a protein-rich plant ingredient.
However, peas are also a legume, and when they make up a significant portion of the diet, the story becomes more complex. When used as a main ingredient (especially within the top 10 ingredients on a food label), peas may contribute to digestive upset or even interfere with nutrient absorption in some dogs. More concerning is their possible link to heart disease when fed as a central part of a grain-free diet (1),(2).
The DCM Controversy: What the Research Shows
The U.S. Food and Drug Administration (FDA) began investigating diet-related cases of DCM in July 2018 (1). These reports initially emerged in large dog breeds genetically predisposed to the condition, such as Doberman Pinschers and Great Danes. However, many new cases involved breeds not typically at risk, including Golden Retrievers, Shih Tzus, and mixed breeds.
The common factor? Diets high in peas, lentils, chickpeas, and potatoes, usually labelled as grain-free. The Tufts study examined more than 800 compounds in various dog food recipes and found peas consistently appeared as a top ingredient in diets linked to DCM (1).
DCM affects the heart muscle, diminishing its ability to pump blood efficiently. It often leads to congestive heart failure and, if untreated, death (5). While genetic factors play a role, this emerging nutritional concern has highlighted the importance of ingredient transparency and dietary balance.
A more detailed investigation, reported by NBC News and The Guardian, revealed that peas showed the strongest correlation with compounds associated with DCM (4). Study author Dr Lisa Freeman of Tufts described it as a "piece of the puzzle" that could help researchers focus on key factors behind this concerning trend (4). Although the FDA has not banned peas or other legumes from pet food, it urges caution and continued investigation. The agency acknowledges that legumes have long been used in pet foods without inherent danger, but their prominence in grain-free diets may be a significant variable.
Pet owners are advised to monitor their dog's diet closely, especially if the food lists peas or other pulses prominently among its ingredients. Choosing reputable brands with veterinary nutritionists on staff is another safeguard.
Gut Health Matters: The Role of CaniNectar
While much of the DCM discussion centres around cardiac outcomes, diets rich in legumes may also influence the gut microbiome. Legumes are high in fermentable fibres and resistant starches, which can shift microbial populations in both beneficial and harmful directions.
This is where supplements like CaniNectar may offer value. In a 2023 exploratory study involving UK Border Force (UKBF) dogs, CaniNectar supplementation showed promising trends (3):
- An increase in 'good' gut bacteria (e.g., Faecalibacterium, Blautia)
- A decrease in 'bad' bacteria (e.g., Streptococcus, Treponema)
- Improved stool quality and appetite, particularly in dogs over five years of age
These shifts suggest CaniNectar may support gut resilience, especially when dogs are consuming diets that include peas or other legumes. It does so potentially by helping balance the microbial ecosystem, thereby mitigating side effects such as gas, diarrhoea, or nutrient malabsorption that can result from a fibre-heavy diet.
Why Older Dogs May Benefit Even More
The 2023 study found that older dogs responded more positively to CaniNectar than younger age groups (3). They were 2.3 times more likely to show improved stool quality and over 4 times more likely to show better appetite. This is significant because ageing often brings natural declines in digestive efficiency and microbiome diversity.
Given that many senior dogs are switched to "gentler" diets, which may include more plant matter or grain-free formulations, a supplement like CaniNectar could help maintain digestive harmony and immune function.
Striking the Right Balance: Peas in Moderation
Peas themselves are not harmful in moderation (2). When fed fresh, frozen, or thawed (but not canned), and served as occasional treats, they can add nutritional diversity (2). But when they dominate a diet — as they often do in grain-free formulations where peas, pea protein, or pea flour are listed among the top ingredients — they may displace more bioavailable animal proteins and create imbalances.
Pet owners are encouraged to check ingredient labels and consult their vets, especially if their dog’s food lists multiple legume-based ingredients early in the ingredient panel.
Moreover, choosing foods that meet the nutritional standards of the American Association of Feed Control Officials (AAFCO) and are marked as "Complete and Balanced" helps ensure that essential nutrients, including taurine, are present in adequate ratios (2).
Looking Forward: Research and Responsibility
The Tufts study and FDA investigation have prompted important conversations about the formulation of commercial dog food. While no definitive causal link has been established between peas and DCM, the correlation is strong enough to warrant caution.
Adding a microbiome-supportive supplement like CaniNectar could be one strategy for dog owners who wish to maintain some plant-based ingredients in their pet's diet but also want to safeguard gut health and digestive performance.
It may also open avenues for future research on how microbiota interventions could play a role in mitigating the unintended effects of modern ingredient trends in pet nutrition.
Final Thoughts
Peas, when used appropriately, are not the enemy. But as with all nutrition, context matters. In a pet food landscape increasingly filled with marketing buzzwords like "grain-free" and "ancestral," it’s important to remember that dogs have very different digestive needs from humans.
With thoughtful formulation, clear labelling, and targeted supplements like CaniNectar, it's possible to support digestive health while navigating the evolving world of canine nutrition.
As always, owners should work closely with their vets when choosing a diet, especially if their dog is showing signs of digestive discomfort, food sensitivity, or lethargy. Balancing modern formulations with gut-supportive tools may be the key to ensuring long-term wellness in our dogs, pea protein and all.
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