Navigate the veterinary nutrition minefield

April 13, 2019
Sarah Mouton Dowdy
Sarah Mouton Dowdy

Sarah Mouton Dowdy, a former associate content specialist for, is a freelance writer and editor in Kansas City, Missouri.

Politics, religion and nutrition? From grain-free diets to byproducts, get tips from veterinary nutritionist Dr. Donna Raditic on how to address hot-button pet food issues.

If you step lightly when it comes to talking nutrition with clients, all parties will come through the other end better for it. ( far as touchy topics go, nutrition is on par with politics and religion, said Fetch dvm360 speaker Donna Raditic, DVM, DACVN, CVA, during a recent session. But instead of avoiding it, Dr. Raditic proposed that the best way for veterinary professionals to diffuse the tension is to tackle the topic head-on with honest, straightforward guidance.

With Dr. Raditic's help, let's tread not-so-lightly through some of veterinary nutrition's latest landmines (and a few long-standing ones as well).

Landmine #1: Grain-free diets are dangerous

“What do we know about the relationship between diet and dilated cardiomyopathy (DCM)? A little, but not a lot,” said Dr. Raditic.

Read more about DCM and diet

> Insight and advice from veterinary cardiologists at Washington State University

> FDA update from February 19, 2019

She discussed a 2018 study involving 24 golden retrievers diagnosed with taurine deficiency and DCM and 52 healthy ones.1 Twenty-three of the 24 DCM dogs were fed diets that were either grain-free, legume-rich or a combination of both.

“You should go read this study,” Dr. Raditic said, “because 84% of the DCM goldens had a whole blood taurine concentration that was less than 200 µmol/L, and 16% were in the 200 to 250 µmol/L range. Fourteen of the healthy goldens had a taurine concentration that was either less than 200 µmol/L or in that 200 to 250 µmol/L range. From this study, they are calling goldens with a whole blood taurine concentration < 250 µmol/L taurine deficient and suggesting the need for breed-specific whole blood taurine levels.”

What would Dr. Raditic take home from this?

“Tell your clients not to panic,” she said. “This is not every golden nor every dog eating grain-free, heavy-legume diets. There are a lot of dogs eating these diets without heart issues. But I think it's something we're going to need to start looking at. If I was in practice and had goldens on grain-free or legume-heavy diets, or if I had any concern whatsoever, or if my client had any concern whatsoever, I would check the dog's whole blood taurine concentration. And if I found a deficiency, I would contact the FDA.”

Dr. Raditic also noted that with a diet change and taurine +/- L-carnitine supplementation, 23 out of the 24 DCM dogs showed significant improvement in echocardiographic parameters and taurine concentration.

She has a hunch that further research will reveal that it's more than just grain-free and legume-heavy diets behind these taurine deficiencies. This inkling partly stems from the finding that 23 out of the 24 DCM dogs were eating less of the diet than you would calculate that they needed to maintain their weight. In other words, these dogs were taking in less of the nutrients in the diet that a dog utilizes to synthesize taurine. Dr. Raditic has also seen dogs with DCM and taurine deficiencies that have been fed other diets-including a homemade diet formulated by an ACVN diplomate and a diet fortified with taurine.

“I think research will show that it's multifactorial,” she concluded. “It may be diet itself, it may be the nutrient density, it may be metabolism, it may be genetics. Some breeds may need taurine in their diet straight up. But it's a wakeup call for us to start paying attention. If you don't look, you don't know.”

You avoided that landmine. What's next?


Landmine #2: Pet food companies are poisoning pets and using them as pet food

To get everyone on the same paranoid page, Dr. Raditic shared some excerpts from Ann Martin's 1997 book, Food Pets Die For: Shocking Facts About Pet Food:

“Animal protein” in commercial pet foods can include diseased meat, road kill, and contaminated material from slaughterhouses, fecal matter, rendered felines and dogs and poultry feathers.

The most objectionable source of protein for pet food is euthanized cats and dogs. It is not uncommon for thousands of euthanized dogs and cats to be delivered to rendering plants, daily, and thrown into the rendering vat-collars, I.D. tags, and plastic bags-to become part of this material called “meat meal.”

Dr. Raditic cited a 2019 study that screened 21 over-the-counter (OTC) adult canine diets marketed as limited or single protein source diets for the DNA of 10 different mammalian species.2 And while the screening detected the presence of DNA from one or more species not declared on the label in all 21 diets, cats, dogs, rats and mice weren't among the detected species.

“You should be honest with clients that there is a lot of contamination in the pet food industry and that while the industry has agreed not to use dogs and cats in food, it's only an understanding. It's not illegal,” Dr. Raditic said. “However, I remind clients that it's a business, and it would not make good business sense for pet food companies to harm dogs and cats. It's just common sense.”

Now let's get into all those byproducts ...


Landmine #3: Byproducts are bad

Dr. Raditic shared legal definitions from the Association of American Feed Control Officials (AAFCO) that can be helpful when you need to explain what byproducts are (and often just as important-what they aren't) to clients:

Meat byproducts are the nonrendered, clean parts, other than meat, derived from slaughtered mammals. It includes, but is not limited to, lungs, spleen, kidneys, brain, livers, blood, bone, partially defatted low temperature fatty tissue and stomachs and intestines freed of their contents. It does not include hair, horns, teeth and hoofs.

Poultry byproducts are the nonrendered clean parts of carcasses of slaughtered poultry, such as heads, feet and viscera, free from fecal content and foreign matter except in such trace amounts as might occur unavoidably in good factory practice.

“Using this stuff in pet food isn't bad,” Dr. Raditic explained. “In fact, many of these parts are considered good food in other areas of the world!” (Haggis, anyone?)

On a related note, Dr. Raditic addressed an oft-heard sentiment regarding pet food: You get what you pay for. If you pay a lot, you get good food. If you pay a little, you get garbage.

She said that this might be true but invites her clients to look at it in a more nuanced way.

“The larger companies-and right now, that would be Purina, Mars and Royal Canin-have a lot of money and can buy better ingredients,” she explained. “If I was producing the best byproducts in the world, I would want to be married to one of these big companies who can pay me top dollar.”

In other words, big companies have leverage. According to Dr. Raditic, they have the pocketbooks to get first dibs on the best ingredients, create better quality control measures and hire PhDs and food scientists.

“So when I'm forced to comment on over-the-counter diets (OTC) diets, which I think vary about this much, a large pet food company will usually have the slight competitive edge,” she said.

Therapeutic diets, Dr. Raditic continued, are significantly better diets, and she recommends them for healthy dogs too. Because a veterinarian must sign off on them and because they're meant to be treating medical conditions, they carry a higher liability and are thus more carefully formulated, she said.

Time for a little reading on reading ... 


Landmine #4: To pick the best food, you just have to read the label

“I'm done reading labels,” Dr. Raditic confessed. “I give up.”

Out of 44 nutrients, she noted that pet food labels only talk about four: protein, fat, fiber and moisture.

“I can get more information from a can of Diet Coke,” Dr. Raditic said. “I won't mention a name, but I just asked for some full nutrient profiles on some therapeutic diets and was told, ‘I'm not sure we can share that.'” There is a need for transparency in the pet food industry and improving pet food labels would be a good place to start.

The proof is in the poop

How can you know if you're feeding a better diet? The proof is in the poop. “If the dog or cat has better stools, less stool volume and goes less often, you are now feeding a diet with a higher digestibility,” Dr. Raditic said. For example, if you have a dog that goes from three bowel movements a day to one after changing its diet, you have improved its nutrition. Some dogs, when put on a homemade diet, will go every other day and owners may be concerned thinking their dog is constipated because having several large stools a day has somehow become tied to good health, so it's a good idea to explain this upfront.

Further complicating pet food label matters is the fact that wet ingredients weigh more, which is why they're listed first, said Dr. Raditic. The first three ingredients your eye scans on a label just means that they're wet and weigh more-not that they bring in the most nutrients.

“Pet food companies know how to play with ingredient labels-to manipulate and use them for marketing. It is very frustrating to try to explain this to pet parents,” she lamented.

According to Dr. Raditic, these label games trick pet parents into thinking that their dog's pet food is full of chicken when the main source of protein is primarily plant based with ‘some' meat protein.

Therapeutic diets don't play the label game, which can also be frustrating, said Dr. Raditic. “As an integrative practitioner, trying to get somebody to walk out with a therapeutic gastrointestinal diet that has a label that reads ‘gluten meal, rice, corn, etc.' when they're feeding a diet with a label topped with turkey, yellowtail tuna or free-ranging bison … I mean, seriously?”

The bottom-line advice from Dr. Raditic is to not select pet diets based on the ingredients only.

“They don't even list every ingredient,” she explained, “and you can't tell the quality of the ingredients from reading the label. Let clients know that we need to demand more information on pet food labels; it's not like reading labels on human foods.”

Instead of spending hours reading ingredient labels, Dr. Raditic offered the following guidelines: OTC diets vary very little, therapeutic diets are better, and if you can get your clients to make the food themselves working with an ACVN diplomate, that's the best.

More grain-free talk ahead ...


Landmine #5: Dogs and cats are carnivores, they don't need carbs, and they should only eat a grain-free diet

Dr. Raditic said you should explain to clients that grain-free does not mean carbohydrate-free. Dogs aren't technically carnivores (though cats are obligate carnivores), and both have a cell requirement for a carbohydrate called glucose, which they can get from their diet or produce themselves from protein or fat.

So, clients are partly right, she said. Adult nonreproducing dogs and cats don't need carbohydrates from their diet, but they do need carbohydrates for cell metabolism. However, grain-free doesn't mean that it's free of carbs, as these diets contain peas, potatoes and legumes, which are loaded with carbohydrates.

Next, she tackled the misguided notion that carbs are making pets obese.

“Calories are what cause pets to become overweight or obese,” explained Dr. Raditic. “And whether a calorie comes from a carbohydrate or a protein-and one gram of a carbohydrate or protein gives you four calories, and one gram of a fat gives you eight calories-it still can make the pet fat. At the end of the day, it's still a calorie.”

In other words, the body doesn't label a carb calorie as bad and a protein calorie as good. A calorie is a calorie, and too many calories and not enough burning of calories (exercise) is what leads to overweight and obese pets.

Talk about avoiding politics and religion ...


Landmine #6: Feeding table scraps is one of the seven deadly sins

“There's so much shame surrounding table scraps that I feel like clients are confessing when they tell me about it sometimes,” Dr. Raditic joked. “We've got to quit making people feel so bad.”

Instead of beating her clients up, Dr. Raditic offers direction.

“I have a list of people foods that I actually encourage my clients to share with their pets-things like white meat chicken, fruits and vegetables,” she said. She also includes a list of human foods that aren't safe.

And if clients start to overdo it (i.e. give too many extra calories via table scraps), Dr. Raditic said it can be a good opportunity to suggest they visit a veterinary nutritionist to develop a plan to make their pet's food themselves.

Pet owners have a reason to be skeptical

In closing, Dr. Raditic shared that an unpleasant interaction with a pet store employee served as the impetus for her journey into veterinary nutrition.

“I honestly became a veterinary nutritionist because I prescribed a therapeutic diet, and the client went to the local pet food store where an employee sold her something else. The employee and I had a knock-down, drag-out, and I thought, ‘I've got to know more about this. He knew more than I did,'” she recalled.

One of the things the pet store employee said that stuck with Dr. Raditic was that pet food companies paid for her education, and she noted that Hill's Pet Nutrition just gave 2.2 million dollars to Kansas State University for a new facility, Mars Petcare support of WSAVA's Global Nutrition Committee and Nestle Purina Missouri Program in Small Animal Nutrition. Pet owners read this stuff, and they're not stupid, she explained. It's our job to address this skepticism by knowing and sharing facts not pet food industry marketing.


1. Kaplan JL, Stern JA, Fascetti AJ, et al. Taurine deficiency and dilated cardiomyopathy in golden retrievers fed commercial diets. PLoS One 2018;13(12):e0209112.

2. Fossati LA, Larsen JA, Villaverde C, et al. Determination of mammalian DNA in commercial canine diets with uncommon and limited ingredients. Vet Med Sci 2019; 5(1);30-38.

Sarah Mouton Dowdy, a former associate content specialist for, is a freelance writer and editor in Kansas City, Missouri.