Pawsitively Nutritious Benefits of Organic Diets for Dogs
Like a dog with a bean ... vegan diets found to aid canine health
Vegan diets are healthier and safer for dogs than conventional meat-based diets, according to the largest study to date, as long as they are nutritionally complete.
The diet and health of more than 2,500 dogs were followed over a year using surveys completed by their owners. These assessed seven general indicators of health, such as multiple visits to the vets, and 22 common illnesses.
The researchers found that, for example, almost half the dogs fed conventional meat-based diets required non-routine medication but only a third of the dogs fed vegan diets did so. A separate study in 2021 found that dogs found vegan diets just as tasty as regular dog food.
Some of the dogs in the study were fed raw meat diets and these were marginally more healthy than the vegan dogs overall. However, this may have been because they were on average a year younger.
The damaging impact of western societies overconsumption of meat on the environment and peoples health has become clear in recent years, as well as rising concerns over how farm animals are treated.
There are about 470m pet dogs in the world and an increasing number of pet owners are now considering changing their animals diets as well. About $9bn (6.9bn) of vegan pet food was sold worldwide in 2020 and the sector is growing fast.
Our study is by far the largest study published to date, said Prof Andrew Knight, at the University of Winchester, UK, and who led the study. It revealed that the healthiest and least hazardous dietary choices for dogs are nutritionally sound vegan diets.
The raw meat diet appeared to have marginally better health outcomes, he said. But those dogs were significantly younger, which gives them a health advantage. A substantial body of prior studies have also shown that raw meat diets are much more contaminated with pathogenic bacteria and parasites.
The study, published in the journal Plos One, analysed surveys completed by 2,536 dog owners about a single animal. Just over half ate conventional meat-based diets, a third were fed raw meat and 13% had vegan diets.
Among the findings were that 17% of dogs on conventional diets had four or more visits to the vet over the course of a year, compared with 9% for those on vegan diets and 8% for those on raw meat diets. The percentage of dogs reported to have suffered from health disorders was 49% for the conventional diet, 43% for the raw meat diet and 36% for the vegan diet.
Survey-based studies cannot reveal the reasons for their results but Knight suggested weight problems might be an important factor: One of the most common health problems for dogs is being overweight or obese and it is unfortunately common that when we do tests on the commercial meat-based diets, there are more calories.
We also know the health hazards associated with overconsumption of meat and dairy for people and its often the same ingredients, he said, although in some countries pet food can contain meat deemed not fit for human consumption.
Further research is needed to confirm the findings. The key limitation of our study is that we didnt have a population of animals locked up in a research facility and fed one specific diet without any alteration, Knight said. We studied what real dogs in normal homes ate and their health outcomes. It gives us a good indication as to what the outcomes are for dogs in the real world.
Justine Shotton, the president of the British Veterinary Association, said: There is a lot of ongoing research in the field of vegan dog diets and this paper adds to the body of evidence supporting its benefits. However, there is currently a lack of robust data mapping the health consequences of feeding a vegan diet to a large number of dogs over many years, so we look forward to seeing further research on whether this can meet a dogs dietary requirements over the long term.
Although we would not recommend it, it is theoretically possible to feed a dog a vegetarian diet, but owners would need to take expert veterinary advice to avoid dietary deficiencies and associated disease, she said.
Most of the respondents to the survey were in the UK and other European countries and more than 90% were women, but Knight said this was unlikely to have caused a systematic bias. Knight, who follows a vegan diet himself but does not own a dog, devised and led the peer-reviewed study, which was funded by the charity ProVeg.
Diet and nutrition for dogs
There are lots of types of dog food on the market, including complete dry diets, wet food with or withoutbiscuit mixers, and fresh dog food. So it could be difficult to know what is best to feed your dog!
Generally, a good complete food should provide all the essential nutrients for your dog. Dry food can also be good for your dogs teeth.
Its difficult to give your dog everything they need with a homemade or raw food diet so we recommend buying commercial dog food, rather than making your own. If you decide to give your dog this type of food, always seek veterinary advice first.
The food you need will depend on your dogs life stage
Most foods are now available to suit the different life stages: puppy, adult and senior. These have been formulated carefully to match the needs of dogs at different ages, so make sure you buy the right one for your dog. As your dog gets older, transition to the next food gradually.
Puppies can move on to adult food once theyve stopped growing when this is will vary depending on their size and breed. Check the food manufacturers guidance and speak to your vet to decide the right timing for your dog.
How to change your dogs food
Its important your dogs diet is consistent, as sudden changes could cause an upset stomach.
If you want or need to introduce a new diet, do this over the course of a few days to a week. Start by replacing a small amount of your dogs current food with their new food, and gradually increase the proportion of new food.
How much should I feed my dog?
Check the food packet for a guide to work out the right amount of food for your dog. But be aware that these are only guidelines, and you may need to adjust according to your dogs individual needs.
How much food your dog needs will depend on their activity levels and metabolism, so youll need to monitor their weight and body condition. Heres a useful guide to maintaining a healthy body condition.
Be careful not to overfeed your dog. Obesity increases your dogs risk of arthritis, diabetes and heart disease. If you think your dog may be overweight, your vet will be able to help you with a feeding and exercise plan.
If you're not sure what a healthy weight is for your dog, or how much to feed them, speak to your vet.
Are Grain-Free Diets Bad for Dogs?
What Is Grain-Free Food?
Most of us are familiar with wheat, rice, corn, and barley since these are part of our usual diet. We think of them as carbohydrates or carbs. Whole grains contain protein, fiber, vitamins, and minerals, which makes them healthy both for us and for our dogs.
About 20 years ago, as veterinarians were seeking better diets for dogs with food allergies, nutrition companies conducted AAFCO (Association of American Feed Control Officials) food trials to determine the safety of hypoallergenic diets, some of which were grain-free. These diets have been fed safely to dogs and cats since that time.
Starting about 2005 there was a rise in marketing by pet food companies that promoted grain-free diets as healthier for dogs with health issues or allergies, or because grain-free diets had fewer fillers.
The word filler itself is misleading, as filler is defined as an ingredient that adds bulk to the food but no nutritional value to the pet (i.e. it is not digested). However, fillers added to pet foods are typically in the form of fiber, which feed intestinal bacteria and produce the short chain fatty acids that keep the intestinal tract healthy. Without fiber/fillers, the pet food would not be complete and balanced.
Pet parents clearly want the best for their dogs. The information most readily available to pet parents online and pet stores at this time suggested that grain-free diets were healthy, even if veterinarians were not always on board.
Is Grain-Free Food Linked to Health Conditions in Dogs?
Dilated cardiomyopathy (DCM) is a breed-related disorder causing dilation and thinning of the chambers of the heart. This can lead to heart failure, arrhythmias, and sudden death. The breeds most commonly affected are theDoberman Pinscher, Golden Retriever, Great Dane, Boxer, andCocker Spaniel.
In 2018, the FDA began receiving reports of dog breeds with DCM that typically do not develop this disease. The common factor among these dogs was they all were eating grain-free or boutique (uncommon) diets. Once they were placed on a diet with grains, the dogs slowly recovered.
Seventeen peer-reviewed studies over the last 4 years have been published, with 1,382 dog cases and 20 cat cases (as of Dec. 23, 2022) reported to the FDA. The case numbers are also believed to be underreported, as the pets need a workup by a cardiologist and the FDA reporting process can be difficult. The original theory that this could be a taurine deficiency in these diets, which had been seen in rare cases, has proven to be more complex.
One study in 2018 found taurine deficiency only in Golden Retrievers eating a grain-free diet. However, future studies could not find taurine deficiency in any breed, including the Golden Retriever. There does appear to be an association between pulses (part of the legume family, including peas, lentils, and chickpeas) being high in the ingredient list in the reported cases.
There are no other major health issues associated with grain-free diets outside of DCM. Dogs given over-the-counter diets for food allergies may continue to experience itching, vomiting, or diarrhea if the diet was not made in a facility specifically dedicated or cleaned to prevent cross-contamination of proteins for food-allergic pets.
Why Would Dogs Be Recommended Grain-Free Food?
Celiac disease, a disease of gluten intolerance that is very common in people, is very rare in dogs. There is a line of Irish Setters in the United Kingdom that have gluten intolerance, similar to celiac disease. Some Border Terriers have epileptoid cramping syndrome, which is relieved by a gluten-free diet. These are the only known dogs with gluten-responsive medical issues.
Dogs with food allergies may benefit from a limited ingredient diet or hydrolyzed diet, and some of these diets are grain-free. Therapeutic prescription hypoallergenic diets, which have gone through AAFCO or more advanced feeding trials, have not had reports of dogs developing DCM to date. These are the diets that veterinarians recommend, not just because of the DCM issue.
Prescription hypoallergenic diets are made under rigorous protocols to prevent cross-contamination of ingredients, as well as testing for any rogue ingredients. Dogs are much less likely to have flare-ups of allergies or gastrointestinal issues because of these strict protocols. While the prescription diets are expensive, pet parents may ultimately save money on veterinary bills due to fewer relapses of their pets signs.
Should I Feed My Dog Grain-Free Food?
If you are considering a grain-free diet for certain reasons, including that your pup wont eat their regular diet, is constantly itchy, or has a sensitive stomach, the first step is to seek veterinary advice.
A medical issue may need to be addresssed in addition to the one you think is already happening. Also, your vet may recommend a different diet based on your dogs age or overall health, based on clinical signs.
Featured Image: iStock/VYCHEGZHANINA
References
Sanderson, SL. Pros and Cons of Commercial Pet Foods (Including Grain/Grain Free) for Dogs and Cats. Veterinary Clinics of North America: Small Animal Practice. 2021 May;51(3):529-550.
Freeman, L. Diet-associated dilated cardiomyopathy: The cause is not yet known but it hasnt gone away. Clinical Nutrition Service, Cummings School of Veterinary Medicine, Tufts University. February 2023. Ibid.
Questions & Answers: FDAs Work on Potential Causes of Non-Hereditary DCM in Dogs. US Food and Drug Administration. December 2022.
WRITTEN BY
Jennifer S. Fryer, DVMVeterinarian
Jennifer S. Fryer, DVM graduated with Honors from Brown University with an AB in Development Studies, an interdisciplinary study of the...
