Grain-free diets are an increasingly popular variation of dog foods, but there is no science-based evidence that is leading the grain-free trend. There is no definitive reason for why this trend has taken off, the thought is that it is a carry over from human-based nutritional trends. But the idea that some dogs may have a sensitivity or allergy to grain is a misconception. Food-based allergies are uncommon, but when they do present themselves, it is almost exclusively to the protein source.

Due to the popularity of these diets and an increasing frequency of complications, numerous studies have been done on the nutritional requirements of domesticated dogs, specifically looking at grain and grain-free diets. The undisputed take-away is that dogs have evolved a requirement for the fundamental components of grains.

Critically, dogs being fed grain-free diets, primarily diets with alternative carbohydrate sources, have a drastic increase in incidence of serious, potentially fatal heart disease in dogs. The problem, dilated cardiomyopathy (DCM), is uncommon, but not rare; we have diagnosed multiple cases of dogs with DCM due to grain-free diets here at YVC.

A few critical, initial points regarding grain-free diets and DCM:

• DCM caused by a grain-free diet is a very serious disease; most dogs will die or be euthanized within months of diagnosis.

• DCM will sometimes, but not always resolve when the pet is converted to a diet with grain.

• There is no supplement that can be added to the grain-free diet that will reliably prevent the problem or reverse the heart damage once it occurs.

• There are no medications we can use to effectively manage DCM.

Dogs that have DCM will initially have no symptoms. The only way to definitively diagnose DCM is with an echocardiogram (ultrasound exam of the heart). At YVC, our recommendation for screening dogs where we have a suspicion of DCM is to start with a physical exam, followed by a general blood profile and chest x-rays, and then an echocardiogram (all of which can be done here at YVC).

It is important to note that most dogs that eat a grain-free diet do not develop DCM, so we believe it is a reasonable option for dog owners feeding a grain-free diet to simply switch their dog to a diet with grain without doing diagnostic testing.

For dog owners that are still determined to feed a grain-free diet despite the risk of DCM, there are options. Hill's Prescription Diet, Hill's Science Diet, Royal Canin, and Purina Pro Plan Veterinary Diets are all formulated by board-certified veterinary nutritionists that have developed grain-free foods that will NOT cause DCM. These are the only grain-free foods that have not been implicated in the problem.

(Hill's, Royal Canin, and Purina occasionally add and eliminate products. We try to keep this list up to date, but it is possible that there are additions or deletions of which we are unaware.)

HILL'S PRESCRIPTION DIET GRAIN-FREE DOG FOOD

• CANNED d/d duck

• d/d salmon

• DRY d/d potato and duck

• d/d potato and salmon

• d/d potato and venison

HILL'S SCIENCE DIET GRAIN-FREE DOG FOOD

• DRY Sensitive Skin/Stomach Grain Free

HILL'S SCIENCE DIET NO CORN/WHEAT/SOY

• DRY Puppy No Corn/Wheat/Soy

• Adult No Corn/Wheat/Soy

• Adult Small Bites No Corn/Wheat/Soy

• Large Breed No Corn/Wheat/Soy

• Adult 6+ No Corn/Wheat/Soy

• Adult 7+ No Corn/Wheat/Soy

ROYAL CANIN GRAIN-FREE DOG FOOD

• DRY Selected Protein PD

• Selected Protein PR

• Selected Protein PV

• Selected Protein PW

• Selected Protein PW Moderate Calorie

• Selected Protein PW Large Dog

• LOAF Selected Protein PD

• Selected Protein PR

• Selected Protein PV

• Selected Protein PW

• Selected Protein PW Moderate Calorie

• Selected Protein PW Large Dog

PURINA PRO PLAN NO CORN/WHEAT/SOY DOG FOOD

• DRY Pro Plan Adult Sensitive Skin and Stomach Salmon and Rice Formula

• Pro Plan Adult Sensitive Skin and Stomach Small Breed Salmon and Rice Formula

• Pro Plan Adult Sensitive Skin and Stomach Lamb and Oatmeal Formula

• Pro Plan Adult Sensitive Skin and Stomach Turkey and Oatmeal Formula

• Pro Plan All Ages Sport Active 27/17 Turkey and Barley Formula

• WET Pro Plan Adult Sensitive Skin and Stomach Salmon and Rice Entree

• Pro Plan Complete Essentials Grain Free Adult Turkey and Sweet Potato Entree

• Pro Plan Complete Essentials Grain Free Adult Chicken and Carrots Entree

• Pro Plan Complete Essentials Grain Free Adult Beef and Peas