Dog Food Allergies and Symptoms

Updated June 26, 2019
Young beagle waits for food

While many dogs experience symptoms that would make one think they have food allergies, it's not a common as many dog owners believe it to be. There can be several kinds of allergies in dogs and knowing the cause can help you and your veterinarian ease your dog's discomfort.

What Are Dog Food Allergies?

A dog can develop an allergic response to ingredients based on his immune system. Some dogs, and people, have an immune system that sees certain ingredients as "attacking" the body as a virus or bacterial infection would. Even though the ingredient itself may be completely harmless, the body doesn't see it that way and creates an allergic response to protect itself. This response involves the common symptoms found with food and other allergies.

How Common are Dog Food Allergies?

If you read the internet or read the labels on many new dog food products, you might think that dog food allergies is a big problem. However, according to the Veterinary School at Tufts University, dog food allergies are not as common as made out to be and about ten percent of all allergy incidents in dogs are related to food. Many of the symptoms are common to other types of conditions and because it's difficult to test reliably for a food allergy, it's easy for dog owners to believe an allergy is the cause when the dog could be dealing with other medical issues.

Common Dog Food Allergens

For dogs that have a food allergy that has been diagnosed by a veterinarian, there are a few ingredients that appear to be common offenders. These include:

  • Chicken
  • Beef
  • Lamb
  • Pork
  • Rabbit
  • Fish
  • Dairy products
  • Eggs
  • Soy
  • Wheat

Some dogs can have an allergy to vegetables such as potatoes or certain grains, but this is not common and allergies most often are related to proteins. Dogs usually will also be allergic to more than one ingredient.

Woman taking food for dog

Typical Symptoms of Dog Food Allergies

There are many symptoms that can be associated with a food allergy. Most involve reactions on the skin but gastrointestinal upset and respiratory problems can also occur.

Allergic Skin Reactions

Food allergy reactions on a dog's skin include excessive scratching which can lead to inflamed rashes, scaly skin, patches of hair loss and open sores. You may see them chewing on their feet, legs, tail and anal area and also rubbing their faces against surfaces to relieve itching. They may also shake their heads if they scratch at their ears and develop ear infections as a result.

Respiratory Reactions

Although this is not as common with dogs with food allergies, you may see some symptoms related to the dog's respiratory system. This can include sneezing and difficulty breathing.

Gastrointestinal Reactions

The discomfort of dealing with other allergic reaction symptoms can lead to nausea, vomiting and diarrhea. You may also notice some more flatulence than usual. You may also notice some weight loss if the stomach problems persist and a general lack of appetite.

Behavioral Changes

Finally, it's not unusual to see a dog suffering from any type of allergy have behavioral changes. This is due to them feeling so miserable from the symptoms that you may see them more lethargic, skittish or grumpier than usual. They may also seem restless which is related to how uncomfortable they are feeling.

Rarer Symptoms of Food Allergies in Dogs

Although these are rare, some symptoms that have been found in cases of food allergies in dogs are seizures and urinary tract infections.

Treating the Symptoms of Dog Food Allergies

A veterinarian will work to treat both the allergy and the specific symptoms to make your dog more comfortable. Some treatments may include:

  • For skin and respiratory problems your veterinarian will most likely prescribe an antihistamine and corticosteroids to bring down the inflammation.
  • They will also recommend immune modulators like cyclosporine to help mitigate your dog's body from reacting to the allergen.
  • Apoquel may be prescribed which is a medication that treats the inflammation that affects a dog with all types of allergies.
  • If your dog has stomach problems related to an allergy, your veterinarian will prescribe medications for diarrhea and vomiting although they may also just have you provide the dog with a bland diet and supplements such as canned pumpkin or bone broth.
  • In addition to a change in diet, your veterinarian may suggest the use of supplements such as fish oil which has omega three fatty acids to help support the skin.

Diagnosing Dog Allergies

One of the reasons that dog food allergies seems more widespread than it actually is relates to how hard it is to diagnose the condition. There are blood and skin tests that a veterinarian can perform and even ones that can be purchased over the counter by pet owners but the research so far indicates these tests are not reliable. The most reliable way to diagnose a food allergy is an elimination diet.

Elimination Diets

The process for an elimination diet will vary based on each individual dog's dietary and medical history. Your veterinarian will work with you to create a diet which usually includes switching your dog to eating a protein they have never tried before. Common proteins used in elimination diets are rabbit, kangaroo, alligator, yak and fish because they fit the right profile and tend to be proteins the average dog hasn't had in their regular kibble. In order for an elimination diet to work, you will need to adhere strictly to it and this includes any treats and chews that you give to the dog as well. The minimum time frame recommended for elimination diets is 10 weeks.

Hydrolyzed Diet

Another option is to feed a hydrolyzed diet which is one where the protein has been treated with water to break it down so that it no longer triggers an immune response. If your dog has a food allergy, it may clear up once switched to a prescription hydrolyzed diet. Your veterinarian is the best source to decide which route to go as some dogs can still have a sensitivity to the hydrolyzed protein and continue to have an allergic reaction.

Person Giving Food To Dog At Home

Food Allergies and Your Dog's Food

Some dog owners who suspect a food allergy will forego an elimination diet and testing and go with a commercially available diet. The idea is that switching a dog's diet will remove the allergy. The problem with this is that if your dog truly has an allergy to a food ingredient, switching them to a new diet may solve the problem but dogs with food allergies are known to develop allergies to new foods over time. It also won't tell you if your dog actually has other allergies unrelated to food and your dog will miss out on having those treated by a veterinarian.

Hypoallergenic Diets

While there are diets marketed as "hypoallergenic" there really is not a commercially available diet that is truly allergen-free. Most of these diets use proteins like rabbit, lamb, venison or some types of fish. It's possible that a diet like this will work for your dog if he has a food allergy, but realize it's also just as possible they develop an allergy to the protein used in the "hypoallergenic" food. Many limited-ingredient diets may also not be "pure" regarding those ingredients, as more than one type of food will be manufactured in the same place and trace amounts of ingredients you wish to avoid can show up in the "hypoallergenic" food.

Home-Cooked Diets

Some dog owners will opt to feed their dog a home-cooked diet. This can work for a dog with food allergies but you should discuss the diet with a veterinarian first to insure you have the ingredient mix correct. You should also use a veterinary nutrition service to make sure you get the right amount of supplements in the diet to keep your dog healthy.

Helping the Food-Allergic Dog

While there are many diets on the market now that market themselves as being grain-free or hypoallergenic, if your dog is suffering from an allergy the best thing you can do for him is to work with a veterinarian to find the right diet. You first want to make sure your dog's allergies really are based on food and then come up with a long-term diet that isn't onerous or cost-prohibitive for you and will help your dog to feel comfortable.

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Dog Food Allergies and Symptoms