Gluten remains a hot topic, and more owners today are searching for gluten free dog food for their pets, too. Studies show that majority of dogs are actually not sensitive to gluten, but some definitely are.
A growing body of research demonstrated that gluten sensitivity itself is in fact real, and specific diets can help deal with its damaging effects. Food allergies account for about 10% of all allergies in canines, and this includes sensitivity to gluten.
Over 30% of Americans have eliminated gluten from their diets, and this trend continues into the pet food market with gluten free dog food becoming very popular but costly.
This article will examine how real gluten sensitivity in dogs is, what are the causes and treatments, and whether gluten free dog food can be the answer.
What is Gluten?
Gluten has a glue-like consistency that helps to form dog kibble. It’s achieved through mixing flour with water (3). There are grains which do not contain gluten. These include rice, corn, oats, millet and quinoa.
It is important to bear in mind that a gluten free canine diet may not be grain free, but a grain free diet will always be gluten free.
Surveys show that over a third of Americans are trying to eliminate gluten from their diet, and many owners attempt to do the same with their pet foods.
Summary: Gluten is a mix of two proteins and is mostly found in grains such as wheat, rye and barley. Gliadin in gluten is responsible for most of the damaging effects.
Why is Gluten Bad for Dogs and People?
Gluten isn’t necessarily all-bad. But before we can analyze why gluten may be harmful to dogs, we need to take a look at where this gluten free trend comes from, and that’s human diet.
The truth is that majority of pets and people, including many of those currently on a gluten free diet, can actually tolerate gluten just fine. However, several reports have found many diseases related to either gluten or wheat (4).
In most cases, specific health conditions will result in side effects from consuming gluten. For people, the three most common conditions where gluten should be avoided are:
- Celiac disease
- Gluten sensitivity
- Irritable Bowel Syndrome (IBS)
Note that the same breakdown cannot be replicated with dogs, and we’ll discuss this below.
Celiac disease (CD) is by far the most well-known reason to avoid gluten (5). CD can cause a variety of immune system and gut related disorders (6, 7, 8, 9, 10, 11). However, it’s rare in pets. In fact, there’s no record of dogs ever developing celiac disease.
Non-celiac gluten sensitivity, which has also been observed in dogs in different forms, remains undefined and may not even be real in humans where the symptoms are caused by something other than gluten.
There have been tons of reports of non-celiac gluten sensitivity (12, 13, 14, 15, 16). But a major study found that out of 400 patients experiencing “gluten sensitivity,” only 55 people actually had problems with consuming gluten (17).
This remains by far the most applicable gluten related issue for dogs and other pets.
Irritable Bowel Syndrome (IBS) is another reason to avoid gluten (18, 19, 20, 21, 22, 23). Irritable Bowel Disease (IBD) found in dogs has been shown to be different to human IBS (24). There’s also no evidence currently available that gluten can cause IBD in dogs, or worsen a pre-existing condition in dogs (25, 26, 27, 28).
Research on gluten sensitivity in dogs is still in its infancy, and these reports from human trials can help us better understand what may be the cause of adverse effects from gluten in canines.
Summary: Gluten sensitivity in dogs is different to that in people. However, current studies on gluten consumption in human population may further explain how and why dogs are sensitive to gluten.
Gluten Sensitivity in Dogs
Gluten is digested in the dog’s small intestine by pancreatic enzymes. When a dog suffers from gluten sensitivity, the presence of gluten in the diet causes an inflammatory response in the intestine.
Canine’s intestine inflammation has several consequences, including:
- The atrophy (wasting) of the villi (small projections) in the lining of the small intestine responsible for helping dog’s body to absorb nutrients from food.
- An increase in the numbers of lymphocytes (a type of white blood cell), which are present in the dog’s intestine wall (34).
This damage to the intestine can make it harder for nutrients to be absorbed, eventually leading to malnutrition and weight loss in canines. More unpleasant gastrointestinal symptoms may also occur, such as diarrhea and vomiting. Other signs like skin conditions are possible, depending on the severity of the allergy (35).
In other types of gluten sensitivity in dogs, this process can cause the body to produce anti-gliadin and anti-transglutaminase antibodies. They then enter the circulation, and react and launch an autoimmune attack in the dog’s body.
This is important as these antibodies can attack parts of the canine’s nervous system, causing neurological signs such as ataxia, paroxysmal movement disorders (abnormal movements during an episode) and even epilepsy.
In recent years, science has made progress on the mechanisms of gluten sensitivity both in humans and pets, but it is still not entirely understood. e also need to look at correlation between FODMAPs and dogs with gluten sensitivity (36).
Some people with gluten issues were actually sensitive to FODMAPs and not gluten, which ultimately presents an interesting case to study in pets as well (37).
Summary: Gluten intolerance in dogs is genetic. Presence of gluten in a diet of gluten sensitive dogs can have many detrimental health effects. Other wheat-related causes of food allergies in dogs are also possible.
Is Gluten Free Dog Food Essential?
Gluten is not necessarily bad for all dogs, thus a gluten free dog food diet isn’t always essential. The grains that contain gluten can be a perfectly good source of carbohydrate, protein, fiber, trace minerals as well as vitamins B and E when forming part of a balanced canine diet (38).
However, studies have shown that many animals can be sensitive to gluten, and a gluten free diet may significantly improve health of these patients (39, 40, 41, 42). Evidence is clear that gluten free dog food can definitely help dogs with gluten sensitivity.
Most dogs aren’t sensitive to gluten
A recent rise in perceived food intolerance in humans and the fashion for people to stick to gluten free diets has seen an increasing number of owners wanting to follow these trends with their dogs as well (43, 44, 45).
Despite the popularity, there is no scientific evidence to support that a gluten free dog diet is absolutely necessary to the general healthy canine population.
Therefore, majority of owners don’t have to worry about purchasing gluten free dog foods. However, there are cases (discussed below) where going gluten-free is required for a dog, and other reasons where this can simply be a better choice.
On a separate note, a school of thought also exist with the beliefs based around what dogs would eat in the wild, and gluten sensitivity is often part of that debate.
The major argument there is that since dogs would not have consumed grains in the wild, then grains should not be fed as part of their commercial diet. However, there is evidence to the contrary. Dogs are shown to have genes which allow them to readily digest carbohydrates in the form of starch and therefore grains (46, 47).
Summary: A gluten free diet can significantly improve health of dogs that are sensitive to gluten or wheat-related foods. Gluten free diet is not necessary for healthy dogs that can tolerate gluten, but may be beneficial for other reasons.
When is Gluten Free Dog Food Beneficial?
Unfortunately, food allergies in dogs, such as gluten sensitivity, cannot be prevented (48). The equivalent to celiac disease in dogs is rare. However, there are some specific cases where it may be beneficial for dogs to avoid gluten, and feed a gluten free dog food.
Gluten free dog food can be beneficial for:
- Breeds with known sensitivities
- Dogs with allergies to gluten
- Dogs with epilepsy
Let’s take a closer look at all three of these cases.
Breeds with known gluten sensitivities
There are certain dog breeds that have genetic predisposition to gluten sensitivity.
In some cases this seems to be age-related, and as they reach adult hood they are no longer affected (53, 54). The reason for this is currently unknown. Although the condition is genetic, it is not related to the same genes as in human celiac disease (55).
Soft Coated Wheaten Terriers: It appears that SCWTs are also genetically sensitive to gluten or gluten-related compounds.
PLE is a condition where the intestine becomes damaged and a large amount of protein leaks out and is lost. PLN is a condition with a similar concept as PLE but protein is lost into the urine instead.
The cause is currently unknown but these dogs were found to have a type of gluten sensitivity which may be responsible for affecting canine’s nervous system (40).
In the above three breeds, a properly balanced gluten free dog food diet is probably a good choice right from the start of adoption or birth.
Dogs with allergies to gluten
As we have already concluded, it is definitely possible for dogs to be allergic to gluten. However, the most frequently identified dietary allergens in dogs are not grains but rather of meat origin, specifically beef, and therefore are not gluten related (61, 48).
Once you establish that a dog definitely suffers from gluten (more on how to do that below), then it’s time to completely switch to a gluten free dog food diet.
The most common signs associated with dietary and gluten related allergies in dogs are often skin related (62). Symptoms of canine gluten allergy to watch out for include:
- Excessive hair loss
- Bald patches
- Inflamed skin
- Sores and scabs
- “Hot spots” (red, irritated, itchy areas)
Remember that these signs are also common to many other types of allergies in dogs.
When your dog is suffering from any of the above, it does not necessarily mean that gluten is causing it. It’s necessary to consult with a veterinarian to find what is the actual reason.
Dogs with epilepsy
More recently, a possible link has been shown between gluten and epilepsy in dogs (63, 64). Antibodies produced in response to gluten may act as a trigger to seizures in dogs. But further research is needed as the design of these studies may provide false positives (65).
Summary: Studies show that a gluten free dog food diet can help pets with allergies to gluten, epileptic dogs and breeds that are genetically predisposed to gluten sensitivity.
How to Know if a Dog Has Gluten Sensitivity
Diagnosing gluten sensitivity in dogs is possible, but it takes time to be completely certain. When it comes to dog food allergies, there are two options: blood tests and food trials.
How to use elimination diet
Dog elimination diets normally last from 6 to 12 weeks and must be very strict. Your vet and nutritionist can help to identify an appropriate dietary regime and the right gluten free dog food that does not contain any allergens.
This will need to be trialed over a period of time to see if dog’s allergy symptoms improve. For the period of trial feeding, your pets absolutely cannot eat any dog treats, rawhide, pig ears or flavored medications; only specific foods.
Studies have shown that commercial grain free and gluten free dog food brands can help with a more accurate assessment in the elimination diet challenge since most people can’t do homemade dog food right (73).
Summary: Elimination diet is the only way to find out whether a dog is sensitive to gluten. These diets last 6-12 weeks and must be very strict.
Why is There Gluten in Dog Food?
Apart from contributing towards the nutritional make-up of a dog food, gluten acts as a binding agent. It binds everything in a dry dog food together so that it can be easily made into kibble.
Although ingredients that contain gluten are not a problem in principal, gluten should not be used as a substitute for other good quality protein sources. Reading lists of ingredients on dog food labels can help identify if gluten has been used to increase the levels of protein in its make up.
Some manufacturers use gluten as a cheap substitute for animal protein, and those dog food brands need to be avoided for more than this reason alone.
Higher quality ingredients in gluten free dog food
One perceived advantage to feeding a grain free or gluten free dog food diet is the quality of ingredients in these foods. This also may be true for sources of protein used in dog foods since they are likely to be of better quality and clearly identified.
Overall, grain free dog foods are also likely to contain higher levels of protein. This isn’t surprising, since adding gluten in dog foods – even if it’s not at all harmful to most canines – is a cheaper way to manufacture canine feed (76, 77, 78).
A gluten free diet could range from a homemade dog diet formulated by a veterinary nutritionist to one of the many commercial gluten free dog food brands currently available.
A few brands that manufacture gluten free dog foods are:
- Taste of the Wild Grain Free Formula (A rating)
- Castor & Pollux Organix Grain Free Formula (A rating)
- The Honest Kitchen Grain Free Formula
- Nutro Ultra Gluten Free Formula
- Artemis Grain Free Formula (A rating)
Making a nutritionally well-balanced homemade dog food is a tricky business as is, but ensuring it’s also gluten free adds yet another step to complicate things even further. But it’s doable.
Summary: Sustainability in the pet food industry matters. Gluten isn’t harmful to most dogs, and it acts as a binding agent in kibble. Gluten free dog food may have higher quality ingredients and higher levels of protein.
Gluten Free Foods for a Homemade Diet
If you choose to avoid commercial gluten free dog foods and opt for making your own homemade gluten free dog food, there are a few things you need to be aware of.
First of all, reading labels of every food you buy for your dog is key. Always choose naturally gluten free foods instead of processed foods with a “gluten free” label.
Foods to avoid
Here’s a list of most common foods with gluten your dog needs to avoid:
- Processed foods
- Baked goods
- Wheat (all forms)
A lot of these foods shouldn’t be in your pet’s diet in the first place, but it’s particularly important to avoid them for dogs with gluten sensitivity. Certain foods can be processed in the same facility as gluten (85). Always read labels.
Natural foods to include
Here’s a list of foods that are gluten free which you can use in homemade dog food:
- Oats (gluten free)
- Oils and fats
Remember that dogs can’t eat some of the fruits, vegetables, nuts, oils or grains in the category, so pick only those that are healthy and can be tolerated by a canine’s body.
Dogs on a homemade diet may also need certain supplements for complete balance.
Vets also recommend adding a daily probiotic for dogs. Many human studies found that probiotics can help with processing gluten and inhibiting gluten induced damage (86, 87, 88). We’re also aware of the many benefits of probiotics for canines and how they can improve gut health and strengthen the immune system in dogs (89, 90, 91).
Summary: There are plenty of natural foods that are gluten free which can be used in homemade dog food diet. Reading labels and adding supplements for a complete nutritional balance is important.
Take Home Message
Gluten is a family of proteins, and acts as a binding agent to form kibble.
Most dogs won’t have any side effects from gluten when it’s part of a nutritionally balanced diet. A very small percentage of dogs and some breeds in particular are affected by gluten sensitivities. In this group of dogs, a gluten free dog food diet can be extremely beneficial.
The best way to know if a dog has gluten sensitivity is through elimination diet. Studies have also shown that gluten free dog food diet may benefit canines with epilepsy.
Even though there’s no reason to buy gluten free dog food for healthy pets, it’s possible that this type of dog food may have higher levels of protein and better quality ingredients.