Published: May 2021 | Updated: May 2023
The majority of people know someone who is allergic to strawberries or nuts. One of the five most common allergies or hypersensitivities known to affect dogs involves their food.
Unfortunately, this isn't a well-known fact to many dog parents, so allergies are often blamed on environmental factors. Don't get us wrong, there are times where allergies can be environmental, but food allergies should definitely be looked into if your dog is experiencing allergic reactions.
Food Allergies in Dogs vs. Food Intolerance
A food allergy is different from a food intolerance. Food intolerance has to do with poor digestion. For example, if you are lactose intolerant (like most dogs are), your body can't digest lactase (the enzyme in the milk).
*You aren't allergic to the milk, your digestive system just can't digest it well.*
Food allergies are an immune system response to something it sees as being invasive or foreign to the body. Often, this is protein, but it doesn't have to be meat-related. Proteins that can cause allergic reactions can also be found in grains and vegetables.
Your dog's gastrointestinal tract (mouth, stomach, intestines) protects him from most allergens as up to 70 percent of the body's immune system is found in the GI tract. When your dog eats, the meal’s digestion begins in the stomach. The large pieces of food are broken down into smaller pieces by stomach acid, and then the stomach acid and enzymes in the GI tract work together to break everything down into a form that's able to be absorbed by the body.
Partially digested food then moves into the small intestine and is broken down even further into amino acids. When a whole protein source is absorbed by the intestines, and it hasn't been 'vetted' by the body first, that's when the immune system reacts and begins to fight the 'foreign' body, resulting in a food allergy.
Signs of Food Allergies in Dogs
If your dog has a food allergy, you may notice:
1) Itchy skin
This is also known as allergic dermatitis, or is sometimes referred to as dermatitis in general. Itchy, red, irritated skin isn't often located in one particular area of the body and can be found on any part of your dog.
The most common places irritation occurs include the ears, paws, stomach, and groin region.
Hives, also known as urticaria, may appear within 24 hours of your dog eating the food he is allergic to. If your dog has short fur, it's much easier to notice than a dog with thick, long fur. If you suspect allergies and your dog has long fur, you may have to take a closer look and/or feel around for any hives.
If your dog is experiencing itchy skin or hives, you'll likely notice excessive scratching, biting, and licking on the areas that are most bothered. This must be monitored to prevent infection.
3) Canine GI Issues
When your dog is allergic to a food, you may also notice gas, vomiting, and/or diarrhea.
You may also notice swelling in the ears, lips, or near the eye, or chronic paw infections.
The Most Common Food Allergies in Dogs
Although any food can cause an allergic reaction to sensitive dogs, there are foods that are more likely than others to cause a reaction.
The most common being proteins, particularly those from beef, lamb, dairy products, soy, or gluten.
If your dog experiences an allergic reaction to his food, antibodies begin to build up to react with compounds from the food and symptoms may begin to occur.
Sometimes, dog food allergy symptoms take time to notice, which leaves the pet parent wondering what the exact culprit is. That's why this is a trial and error process when determining what needs changed. In order to reduce the allergy, we must first determine what is causing it.
Removing the Problem Through a Dog Food Allergy Test
As stated above, one of the most frustrating aspects of food allergies is determining which ingredient is causing the reaction. There are several blood, saliva, and hair tests that can assist in determining what is causing the allergy, but these tests are often inaccurate.
Eliminating one food at a time is the most common method veterinarians and veterinary nutritionists use to determine what is causing the allergy. Usually, one protein and one carbohydrate is provided along with a supplement or vitamin to ensure there are no nutritional deficiencies during the elimination trial.
If your dog's symptoms appear to improve on the elimination diet providing only what is given, it's likely the other items from the food were what was causing the problem. If your dog's allergy symptoms haven't improved after 3-4 weeks, then your veterinarian or nutritionist may recommend alternating to a different protein or carbohydrate type.
Probiotics for Dogs With Food Allergies
Although digestion has more to do with food intolerance than food allergy, there is still a correlation between the digestive tract and allergies. If your dog’s digestive tract isn’t in optimal condition, this could result in problems as well.
To ensure your dog’s food is being digested properly, and the GI tract is working to the best of its ability, you should implement probiotics into her daily regimen.
For proper food digestion and nutrient release, your dog's gastrointestinal system needs "healthy" bacteria. Good gut bacteria also protect your dog's immune system by warding off possible pathogens. Healthy bacteria colonies in your dog's system hold pathogen-laden "evil" bacteria at bay.
When there is an imbalance of good and bad bacteria (a disorder known as dysbiosis), your dog is more susceptible to a variety of illnesses, including inflammatory bowel disease, diarrhea, tooth decay, and allergies.
Healthy gut bacteria, and a balance in the gastrointestinal tract, can be achieved through the use of a high-quality probiotic. Since your dog is experiencing allergies, they are also more prone to infection, meaning you’ll want to choose a strain like S. boulardii to ensure the probiotics will continue working if an antibiotic is prescribed.
The Bottom Line
Allergies can be difficult to diagnose, but your dog will appreciate your efforts. You'll certainly see a dog with more stamina, a shinier coat, and an overall change in her health when your dog is back on track without the allergen and probiotics are being used daily to promote a healthier gut.
If you're having trouble figuring out what's causing your dog's condition or getting him back to good health, consult a veterinary nutritionist as soon as possible.