Raw Feeding, Grain-Free and DCM, and Food Allergies

The Raw Feeding Question

Raw feeding, unpasteurised raw meat-based diets (RMBDs), whether commercial frozen-thaw products or homemade, is one of the more contested areas in companion animal nutrition. Proponents cite ancestral diet arguments, coat and energy improvements, and mistrust of kibble processing. The peer-reviewed literature on risks is unambiguous; the peer-reviewed literature on benefits, beyond short-term coat and stool appearance, is essentially absent.

I do not feed raw, I do not recommend it, and I want to explain why with specific numbers rather than blanket warnings.

Pathogen contamination

The FDA’s Veterinary Laboratory Investigation and Response Network (Vet-LIRN) conducted a surveillance study published by Nemser and colleagues in 2014 in Foodborne Pathogens and Disease. They tested 196 samples of commercial raw pet food and found 15 positive for Salmonella, 32 positive for Listeria monocytogenes, and 9 positive for both, a total of 38 contaminated samples, or approximately 20% of raw products tested. For comparison, the same study tested 860 samples of dry kibble, semi-moist food, and treats and found one positive for Salmonella. Raw pet food was between 15 and 24 times more likely to carry foodborne pathogens than conventionally processed food. Similar or worse contamination rates have been found in European studies (Vecchiato 2022; van Bree 2018).

Nutritional adequacy

Freeman & Michel (2001, JAVMA) evaluated 5 raw diets, 3 homemade and 2 commercial, and found that every single diet had multiple nutritional imbalances or deficiencies that would cause long-term health problems. Twenty years later, Vecchiato and colleagues (2022, Animals) analyzed 44 commercial raw meat-based diets. Every product in the study had at least one nutritional concern, and 96% failed hygiene quality thresholds applied to products for human consumption. Davies, Lawes & Wales reviewed the field in the Journal of Small Animal Practice in 2019 and summarized that “investigations of both home- and commercially-prepared raw diets commonly have identified nutritional problems.” The patterns repeat across decades and across countries.

Professional position statements

Every major veterinary organization, the American Veterinary Medical Association, Canadian Veterinary Medical Association, World Small Animal Veterinary Association, American Animal Hospital Association, plus the FDA and CDC in the United States, has issued a position statement recommending against feeding raw meat-based diets to companion animals, primarily because of the zoonotic transmission risk to humans (especially children, immunocompromised individuals, and elderly people in the household). That level of consensus across independent bodies is uncommon in veterinary nutrition and worth taking seriously.

If you want the purported benefits of home-prepared food without the raw risks, the evidence-based alternative is cooked home-prepared diets balanced using a veterinary nutritionist service. BalanceIT.com (University of California-Davis) is the most commonly cited resource; the recipes are built from USDA food database values, balanced to AAFCO profiles, and adjustable to individual dogs. Home cooking is more work than kibble, but it removes the raw pathogen risk and removes the adequacy problems that come from ad-hoc recipes.

Grain-Free, Legumes, and DCM

This is an area where the evidence has continued to develop, and I want to be careful to represent it accurately because much of what you will read online is either oversimplified or actively misleading.

In July 2018 the FDA announced it was investigating reports of dilated cardiomyopathy (DCM) in dogs, including in breeds without known genetic predisposition, eating diets labeled “grain-free” that contained peas, lentils, other legume seeds (pulses), and potatoes as main ingredients. In December 2022 the FDA stopped publishing public updates, citing insufficient data to establish causation. This is not the same thing as exoneration. Independent peer-reviewed research has continued since then, and the picture that has emerged is nuanced:

• The link is specifically to high-pulse, legume-rich diets, not to grain-free as a category. The active ingredient of concern is peas, lentils, chickpeas, and similar pulses appearing in the top 10 ingredients, particularly as primary ingredients.
• Multiple 2023–2025 studies continue to find cardiac differences. Owens et al. 2023 (JVIM) found lower ejection fraction and larger left ventricular volumes in healthy dogs on non-traditional diets versus traditional. Coppinger et al. 2024 (JVIM) found significantly more ventricular premature contractions in Irish Wolfhounds eating high-pulse diets. A November 2025 narrative review in Veterinary Sciences summarized the accumulated evidence and concluded that “these findings suggest a strong link between diet and DCM, particularly regarding legumes.”
• Some industry-funded studies have found no cardiac effect (Leach et al. 2023, Morris et al. 2025). These are real studies and should not be dismissed, but they have shorter follow-up, different methodologies, and industry sponsorship. They demonstrate that not every dog develops detectable change on a grain-free diet; they do not disprove the link.
• Many affected dogs improved after switching to grain-inclusive, low-pulse diets (Freid et al. 2021, Haimovitz et al. 2022, Walker et al. 2022). The condition appears at least partially reversible when caught early.

There is no demonstrated health benefit to grain-free diets for dogs without a diagnosed grain allergy. And as I will show in the next section, true grain allergies are uncommon. The grain-free category exists because it sells well, not because it represents a nutritional advance.

Food Allergies: What’s True and What’s Marketing

Food allergies are one of the most over-diagnosed conditions in pet nutrition. Two facts, well-supported in the peer-reviewed literature, tell you most of what you need to know.

First, true food allergies are rare. The petMD reference figure, based on a range of clinical studies, puts the prevalence of food allergies in dogs at roughly 0.2%, one dog in five hundred. Most “my dog has allergies” cases are environmental (flea, pollen, dust mite) or are something other than allergy entirely, yeast overgrowth, parasitic, or dermatological conditions unrelated to diet.

Second, when food allergies do occur, the offending ingredients are not what the marketing suggests. Mueller, Olivry & Prélaud’s 2016 systematic review in BMC Veterinary Research analyzed the peer-reviewed literature and identified the most common food allergens in dogs by prevalence:

Note what this table says. Animal proteins, beef, dairy, chicken, lamb, occupy the top five slots. Grains as a category appear once (wheat, 13%). The entire grain-free category is premised on the idea that grains are the common allergens, and the peer-reviewed data does not support that. If your dog genuinely has a food allergy, it is overwhelmingly more likely to be to a protein source than to a grain.

If you suspect your dog has a food allergy, the only reliable diagnostic is a veterinarian-supervised elimination diet trial, typically 8 to 12 weeks on a novel or hydrolysed protein with no other food sources allowed, followed by controlled reintroduction. Blood and saliva tests for food allergies are not supported by the veterinary dermatology literature. They produce reliable-looking results that do not match diagnostic elimination trials.

NWL

Questions About Feeding Your Dog?

Nutrition decisions compound over years. If you have a specific question about your own dog, what to feed, when to switch, what supplement to try, how to read a label. I’m happy to answer one. Not a consultation. Not a service. Just a question, answered from eleven years of experience and the peer-reviewed literature this article draws on.

If you’re considering a Lagotto and want to know what we do at Northwest Lagotto, the waitlist and breed pages are the right places to start.

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Primary Sources, Quick Reference

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