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What You Must Know About Dog Foods for Allergic Dogs

March 17, 2017March 16, 2017

If your dog is allergic, you are likely looking for the best dog foods for dogs with allergies, but it’s important to learn more about these diets before developing high expectations. The most popular dog foods for dogs suffering from allergies are diets containing novel proteins or hydrolyzed proteins. These are special diets for dogs with allergies that are meant to help keep the symptoms at bay, but they’re not always as promising as thought. Understanding how they work and what studies have to say about them is important to to make an informed decision.

A Word About Protein

Many dogs who are allergic to dog food are allergic to certain proteins. The primary proteins found in most dog foods consist of lamb, chicken, or beef. According to Cummings Veterinary Medical Center at Tufts University, the most reported food allergies are to chicken, beef, dairy, and eggs.

Food allergies in dogs occur when the immune system perceives a protein found in the food as a foreign invader. The immune system therefore builds up a a response and releases histamine which results in itchy skin and ears, and even annoying ear and skin infections.

Proteins are composed of large molecules that are made up of several smaller units known as aminoacids. Aminoacids play an important role in the proper functioning of cells, tissues, muscles, organs, glands, tendons and arteries. Aminoacids also help repair tissue and play a role in removing waste from the dog’s body.

Because studies tell us that there are really no accurate tests to diagnose food allergies in dogs, the most popular method to diagnose which protein a dog is allergic to remains the dietary elimination trial through the use of dog foods made with novel proteins or foods containing proteins that have been hydrolyzed.

About Novel Protein Diets

In a dietary elimination trial using novel proteins, dogs are fed a diet that generally consists of just one protein and one carbohydrate and all the remaining ingredients are fats, vitamins, and minerals. As the name implies, a novel protein diet consists of a source of protein that the dog has never been fed before and this is why these diets often contain odd or unusual meat sources such as lamb, venison, bison and even kangaroo!

When your vet suggests your dog must do a trial using a novel protein diet, it’s important to stick to the same food for 2 to 3 months and assess whether the diet is working. During this time, it’s imperative that you do not feed your dog anything else other than the novel proteing diet. This means absolutely no treats or table scraps during this period, explains veterinarian Dr. Andy.

If your dog seems to dramatically improve during the feed trial, then this suggests that your dog was allergic to something in his old food. To confirm this though, more proof is needed, and the best way to obtain this is to switch the dog back to the old diet again. If the symptoms recur, then yes, most likely your dog likely had an allergy to a protein in the old diet, but the next thing though is discovering exactly which one so to avoid it.

Did you know? Most dog owners think that grains are the most common culprits for allergies in dogs, when in reality, most pets are allergic to proteins, according to Clinical Nutrition Service at Tuft’s University.

About Hydrolyzed Diets

Hydrolyzed diets, unlike novel protein diets, usually contain less exotic sources of proteins. The term hydrolyzed derives from the Greek word “hydro” meaning water and the word “lysis” meaning “to split.” Put these two words together and you have “to split in water.” Basically, in a hydrolyzed diet for dogs, a molecule of water is added to the protein so that the protein is broken down into smaller molecules.

Remember how it was mentioned before that proteins are composed of large molecules that are made up of several smaller units known as aminoacids? Well, when the protein is broken down, it’s basically split into its smaller components, which consist of amino acid chains (polypeptide chains) and free amino acids.

When the immune system encounters these smaller particles, it’s somewhat tricked into believing that they are no longer the proteins they used to be. Since the immune system no longer recognizes these proteins as a threat, it therefore no longer reacts as it used to.

Nowadays, there are a variety of brands of dog foods that contain hydrolyzed protein. These brands include Hill’s Prescription Diet z/d Ultra Canine, Purina HA HypoAllergenic Canine Formula and Royal Canin Veterinary Diet Canine Hypoallergenic.

Did you know? Infant formula has been hydrolyzed for years to help infants better tolerate cow milk.

Potential For Contamination

When you introduce a novel protein diet or a limited ingredient diet (with no more than 2-3 ingredients) to your dog, you expect to know exactly what you are feeding when you read the food label. However, a recent study on limited ingredient commercial diets found that a large number of these diets contained fish and meat ingredients which were not listed on the label!

This is “food for thought” for those dog owners who are scratching their head wondering why their dogs aren’t improving when put on an elimination trial. Of course they are not, dogs are being exposed to allergens through the very exact food that is supposed to be helping them feel better, what irony!

Before assuming your dog is not responding well to the food trial, it may be therefore be worthy trying a home-prepared diet containing a novel protein that has been carefully formulated by a board-certified veterinary nutritionist. After all, a study has shown that when it comes to an elimination diet for the diagnosis of a canine adverse food reactions, a home cooked diet was equally reliable as an extensively-hydrolyzed diet.

“Dogs might fail to respond to commercial limited antigen diets because such diets are contaminated with potential allergens… Before ruling out AFR (adverse food reaction), a novel protein home-made diet should be considered if the dog is unresponsive to a commercial regimen.”~Ricci R. et al, Journal of Animal Physiology and Animal Nutrition

References:

The Veterinary Journal, Volume 220, February 2017, Measurement of allergen-specific IgG in serum is of limited value for the management of dogs diagnosed with cutaneous adverse food reactions E.A. Hagen-Plantinga et al.
J Anim Physiol Anim Nutr (Berl). 2013 Identification of undeclared sources of animal origin in canine dry foods used in dietary elimination trials. Ricci R et al.
Dog Discoveries: Hydrolyzed Protein in Dog Food
Clinical Nutrition Service at Tuft’s University: What every pet owner should know about food allergies
Veterinary Dermatology 2016; 27 (Suppl. 1), 6–121 Diagnostic value of home-cooked and an extensively hydrolyzed diet (Anallergenic, Royal Canin, France) in the diagnosis of canine adverse food reaction: a randomized prospective multicenter study in 72 dogs MC Cadiergues, A Muller, E Bensignor et al.

The Truth About the Top Best Dog Foods for 2019

December 26, 2018March 15, 2017

You may sometimes find lists of the top best dog foods for 2019 and most likely feel tempted to feed your dog those foods that rank the highest. Here at Dog Food Reviews, you won’t find a list of the best dog foods for 2018 and neither a list of the best dog foods for 2019. Indeed, you won’t even find the best dog foods for 2017 or any previous years and you won’t find such reviews for the near years to come. Why is that? For a very good reason, and a very important one too: dog food recommendations are not good for all dogs, and they have the potential to do more harm than good.

A Matter or Nutrigenomics

Those who understand the science of nutrigenomics know for a fact that what is good for one dog may be poison to another.

This is why if you read through the highest ranking food reviews you will find several dog owners reporting that their dog couldn’t seem to tolerate such food. These people are not being party poopers, because here’s an important fact: Every dog is different, and this is often a matter of genes.

Nutrigenomics is the scientific study of the interaction between nutrition and genes. This term has become quite popular nowadays courtesy of Dr. Jean Dodd’s book “Canine Nutrigenomics, the New Science of Feeding Your Dog for Optimum Health.”

According to the science of nutrigenomics, the foods both us and our dogs eat communicate with our cells and control our genes.

We already knew that parents pass down to their children genes that determine whether a child has brown eyes or red hair, and along with those, genes that predispose towards health or disease, but we didn’t know until recently how much quality of diet has the potential to influence genetic expression.

Parents who therefore make unhealthy food choices can influence their children, paving the path towards an unhealthy gene expression, but fortunately, unlike natural eye color or hair color, this can be changed through improved dietary lifestyles.

Individual Reactions to Food

So why does one dog seem to thrive on a certain dog food while in the case of another dog, that same exact food acts almost like a poison?

It’s because some dogs may have a genetic predisposition to develop certain food sensitivities towards certain ingredients. A dog food can be therefore loaded with beneficial ingredients, but those ingredients won’t be able to reach their full potential in the body of a dog that has an intolerance towards them.

We see this often happen among humans too. To a normal child, a packet of peanuts offered during a flight can be a fun form of entertainment and a healthy snack, but give it to a child with a peanut allergy and the child develops hives and facial swelling, or in more severe cases, death through narrowing of the airways from anaphylactic shock.

In the same way, a dog with digestive issues may thrive on a diet of lamb and rice, while another dog may have an intolerance and develop itchy, dull skin. Just as in people, there are individual variances on how the body reacts to certain foods. It’s therefore impossible for a food to be crafted in such a way as to meet the needs of all dogs on this planet and cause all dogs to thrive on it.

A List of the Top Best Dog Foods

With this is mind, it’s redundant to compile a list of the top best dog foods for 2019 or for any given year. Sure, many dogs may thrive on a certain food, but several may not.

There are way too many variances and this is why those dog food reviews out there are a mixed bag of glorious raves and infamous rants. You’ll therefore have the dog owner who swears on the benefits of a certain food, and then you’ll have a dog owner who paid dollars and dollars on vet bills because their dog got sick on it.

On top of that, consider that if you see too many rave reviews, some of those reviews can be biased. Pet food companies may easily hire a bunch of people to post positive reviews so to balance out the negative ones. The tricky part is that you will never know that, considering these fake reviewers astutely post as the average dog owner promoting the food as if it was gold, miraculously solving Rover’s skin issues once and for all.

So does this mean that there is no such thing as the top best dog foods of 2019? It simply means that you must tread with caution before getting too enthusiastic about one food or avoiding another like if it was the plague. For sure, there are dog foods that are far better than others, but the ultimate answer as to how good or bad a food is, ultimately boils down to the individual dog.

“Since each dog has his own genome, a food that benefits one dog might not create the same effect for another-or might even prove harmful.”~Dr. Jean Dodds, Diana Laverdure

Can I Feed My Dog a Vegan or Vegetarian Diet?

March 16, 2017March 15, 2017

If you are on a vegetarian or vegan diet, you may be wondering at some point “Can I feed my dog a vegan diet too?” While dogs may be interested in eating green beans, carrots and peas, given the choice, dogs are particularly drawn to a meat-based diet. If we carefully look at the way a dog’s body is designed, we can get some hints as to what type of diet they were built for. Many veterinarians and veterinary nutritionists are increasingly concerned about the growing trend of vegans and vegetarians trying to let their dogs and cats join their dietary habits; however, doing so can even cause problems that may even lead to some serious nutritional deficiencies.

A Subject of Debate

First off, are dogs carnivores or omnivores? This remains a strong subject of debate. On one hand we have those who strongly believe that dogs are carnivores.

Since wolves are the dog’s ancestors and dogs and wolves share the same number of chromosomes, aligned in 39 pairs, it comes quite natural to conclude that dogs must be carnivores just like wolves are. Even by looking at the dog, one may easily see a body designed for eating meat with those sharp canines.

On the other hand, we have those who believe that dogs must be omnivores. While wolves are the dog’s ancestors, it must be remembered that there are likely 15,000 (or more) years separating dogs from wolves. At some point, when dogs separated from wolves, they must have undergone significant changes. One of them includes the ability to digest starch, as reported in a study.

These changes may cause many to assume that dogs must be omnivores, considering that dogs can survive on a diet with no meat.

As seen, both sides of the debate sort of make sense, but which side is true? First, it may help to get a closer insight into the definition of certain terms.

A Closer Insight

So let’s define a bit more the terms carnivores and omnivores.. When it comes to carnivores, the term is used to depict animals that derive their energy and nutrients from a diet mainly or exclusively composed of meat, bones, internal organs and animal tissues.

Notice how the above definition contains the words “exclusively” in bold letters. Usage of this emphasis is to make an important distinction between obligate carnivores and regular carnivores. What’s the difference between the two? Here are some quick definitions.

Some animals are classified as obligate carnivores which means that they entirely depend on eating animal flesh. Examples of obligate carnivores include cats, lions and tigers. Obligate carnivores (also known as true carnivores) are not equipped with the correct type of physiology to digest vegetable matter and will suffer serious consequences if they do not eat meat. For instance, if a cat’s diet lacks vitamin A, arachidonic acid and taurine, which are only found in meat, cats risk getting seriously sick.

Then we have animals that are classified as facultative carnivores meaning that, on top of eating meat, they also consume non-animal foods. And then, we have omnivores, animals who consume both animal and non-animal food. Examples of ominivores include pigs, chickens and humans. Omnivores are capable of consuming both vegetable manner and meat.

What Exactly are Dogs?

So are dogs carnivores or omnivores? Or perhaps somewhere in between? If we look closely at dogs, we will see that their anatomy, physiology and mind are designed for eating meat. Dogs are equipped with teeth meant for tearing flesh and grinding bone. Their eating style also reflects the eating style of carnivores: rip a chunk of meat off and devour it, letting the gastric juices take care of the rest.

Even the gut transit time of dogs reflect those of carnivores. Not to mention their behavior, dogs are geared to follow the predatory sequence (scan, stalk, chase, grab-bite, kill-bite, dissect and consume). Even though the sequence is truncated in some dogs who were selectively bred for herding, the tendency to chase is still alive nonetheless.

However, let’s not forget about domestication. A key finding of the study conducted by the University of Uppsala in Sweden found that dogs have between 4 and 30 copies of the gene that codes for amylase, the special enzyme that’s responsible for breaking down starch. Wolves, on the other hand, have only two copies of this gene.

So where does this put dogs? Are dogs omnivorous since they can digest starch? First of all, in humans, amylase is produced in saliva, hence the saying “the digestive process starts in the mouth.” In dogs instead amylase is expressed only in the pancreas (Axelesson et al, 2013) .

Secondly, we don’t know yet how many copies of these genes need to be present to qualify an animal as omnivorous, and therefore the answer remains unclear. We do know though that dogs do not thrive on a high starch diet as it has caused obesity and chronic disease. As Doug Kneuven says it in the quote below, goes a long way.

“To say that because dogs can digest starch proves that they thrive on a high starch diet is like aserting that because people can process ethanol and glucose we thrive on a diet rich in rum and cookies!” ~Doug Knueven

About Vegetarian Diets

It is tempting for dog owners to try to feed dogs a vegetarian diet, either because of personal values, ethical considerations or religious beliefs, but these may harm dogs if these vegetarian diets do not meet some important requirements. While it is possible to feed a vegetarian diet, it’s important that it is at least supplemented with synthetic sources of essential nutrients.

Commercial vegetarian diets must state somewhere on their bags whether they are complete and provide all the essential nutrients dogs need.

The problem with vegetarian diets is that they tend to lack essential nutrients and may therefore cause deficiencies. Consider that puppies are at most risk for nutritional deficiencies than adult dogs and dogs on vegetarian diets may require more frequent screenings to evaluate health.

If you are considering a vegetarian diet for your dog, the most important word here is “careful planning” so to ensure you meet your dog’s nutritional requirements. Generally, vegetarian diets that incorporate protein from eggs or dairy are less risky than diets based solely only on proteins from plants, points out veterinary nutritionist Dr.Cailin R. Heinze. Homemade vegetarian diets should therefore be reviewed by a veterinary nutritionist such as a DACVN Diplomat of the American College of Veterinary Nutrition.

“As a veterinary nutritionist, I use meat-free diets quite a bit to help manage various health concerns. The challenge is that designing these diets is not the easiest thing to do.”~Dr.Cailin R. Heinze.

References:

Canine Nutrigenomics – The New Science of Feeding Your Dog for Optimum Health, By W. Jean Dodds, DVM, Diana Laverdure
Cummings Veterinary Medical Center at Tufts University, Vegan Dogs – A healthy lifestyle or going against nature?

Preservatives in Dog Food: The Good, The Bad and The Ugly

March 26, 2018January 23, 2017

With a past as a scavenger, you may not expect Rover to turn his nose up at an expired bag of food. Yet, pet food manufacturers do their best to ensure your dog gets his food at its peak of freshness. Therefore, to prevent your dog from getting into a bag of stale kibble, preservatives are often added to prolong shelf life after being manufactured. However, not all preservatives are created equal. Knowledge is power if you want to ensure your dog eats food that is healthy and not full of dangerous preservatives. So here are the good, the bad and the ugly of dogs food preservatives.

The Good

Most dog food companies will proudly announce on their labels their use of natural preservatives. These natural preservatives often encompass antioxidants such as vitamins known for their preserving properties.

Tocopherol, a naturally occurring chemical compound related to Vitamin E, is often used, and so is ascorbate or ascorbic acid, also known as vitamin C. In some cases, rosemary extract may also be used. Generally, such natural preservatives are considered fairly safe.

A word of caution is needed though in regards to foods that are preserved with natural preservatives. According to veterinary nutritionist Dr. Cailin Heinze, there is evidence that natural preservative may not be as effective in assuring long shelf life as synthetic preservatives which means that as a consumer you will have to pay attention to those expiration dates.

The Bad

Artificial preservatives, on the other hand, may often be a far cry from being healthy. If your dog’s bag of treats has propylene glycol listed, consider that this is a far less toxic version of ethylene glycol, yes, the infamously toxic automotive anti-freeze.

What is such a product doing in your dog’s food? It acts as humectant and preservative. In other words, it keeps food moist and helps increase shelf life considering its anti-fungal and anti-microbial properties.

Currently, propylene glycol is listed as a Generally Recognized As Safe (GRAS) ingredient. However, this acronym is not very reassuring. The word “generally” is iffy and for dog owners who love pets it would feel much better if that word was substituted for “totally.”

Propylene glycol has known to have potential for causing blood toxicity which is why propylene glycol’s use in cat has been banned. According to the Pet Poison Helpline, semi-moist cat foods that contained up to 5-10 percent caused cats to suffer from Heinz anemia.

In dogs instead, its use is still permitted. A study published in Food and Cosmetics Toxicology found that when propylene glycol was fed to dogs at a concentration of approximately 8 percent for two years, it failed to provide any adverse effects.

So yes, propylene glycol in small doses won’t likely harm your dog, but who would want a product listed by the Pet Poison Helpine as toxic added to a dog’s moist food or treats, even if in small amounts?

“As with any chemical, it’s the dose that makes the poison….. The amount of propylene glycol that a dog would be expected to ingest in a commercial dog food containing propylene glycol would not be considered enough to cause poisoning.” ~ Ahna Brutlag, veterinary toxicologist

The Ugly

If using a toxin related to antifreeze wasn’t scary enough, consider that some dog treats may be preserved using a chemical additive known as ethoxyquin. Etoxyquin is a preservative that is often found in dog foods containing fish ingredients. The problem with ethoxyquin is that ethoxyquin is also used as a pesticide and a hardening agent to manufacture synthetic rubber.

This preservative has been suspected as a potential cause of liver and kidney cancer in dogs and has been under investigation by the Food and Drug Administration.

Etoxyquin was approved as a food additive and antioxidant preservative for over 45 years ago; however, around the 1990s the FDA’s Center for Veterinary Medicine (CVM) started receiving worrisome reports of dogs developing skin allergies, organ failure, behavior problems and cancer. Studies conducted by the manufacturer found a dose-dependent increase in liver enzymes in the blood which evoked the Center for Veterinary Medicine to ask the pet food industry to lower the maximum allowed amount of ethoxyquin in dogs foods from 150 ppm to 75 ppm.

For those interested in some research on this matter, you can read this interesting letter by veterinarian Gloria Dodd, DVM: Ethoxyquin, carcinogenic, toxic food preservative in pet foods: a letter to the FDA.

Other worrisome preservatives found in some dog foods are butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) used in some dog foods for the purpose of preserving fats preventing them from being oxidized and going rancid. Both of these preservatives were found to cause cancer in laboratory animals.

The Bottom Line

As seen, preservatives can do more harm than good in some cases. Sure, organizations tell us that they are toxic in large amounts, but that shouldn’t mean they are totally fine to use. Most dog owners nowadays want to know what is in their dog’s food and they want ingredients that are as natural as possible.

Most people know what rosemary is and it is listed by the ASPCA as a non-toxic plant, and everybody knows about the benefits of vitamin E and vitamin C.

If you want to avoid artificial preservatives, look for those foods that contain only natural preservatives. Alternatively, you can try canned food or frozen foods which are generally made of fresh ingredients, explains the Whole Dog Journal.

Or better, if you want to avoid chemicals altogether, conduct some research on how to make a homemade diet or switch to a raw diet if this is something you are interested in. But be careful though, as these diets need to be nutritionally complete. There are several books on the subject and you can always consult with a dog nutritionist for advice to ensure the diet is nutritionally complete.

References:

Cummings School of Veterinary Medicine at Tufts University: Dear Doctor – Preservatives in pet food
Pet Poison Helpline: Propylene Glycol
Weil CS, Woodside MD, Smyth HF Jr, Carpenter CP. “Results of feeding propylene glycol in the diet to dogs for two years,” Food Cosmet Toxicol 1971 Aug;9(4):479-90.