Overview of Dog Food Allergies and Symptoms

Puppy scratching himself

Dog food allergies and sensitivities have become a common problem for dogs as well as people. While posing an inconvenience, it can be a huge relief to discover that what appeared to be a major health or behavioral problem can actually be resolved with a simple adjustment of diet.

Symptoms of Dog Food Allergies

One of the main symptoms of a food allergy in dogs is itchy skin. This can manifest as

  • Excessive scratching
  • Sores
  • Foot, leg and tail chewing
  • Head shaking
  • Hair loss
  • Face rubbing
  • Anal itching
  • Recurrent ear infections

Food allergies are often overlooked because skin problems are assumed to be caused by other health issues such as fleas, mange or external allergens including pollen and dust.

Food allergies can manifest symptoms other than skin reactions including:

  • Vomiting
  • Diarrhea
  • Flatulence
  • Sneezing
  • Asthma like symptoms
  • Seizures
  • Behavioral changes

In some cases, an allergy is not suspected because the dog has eaten the same food for years with no reaction. Like people, dogs can suddenly develop a sensitivity or allergy to a particular food that has not previously posed a problem. Additionally, dog food manufacturers sometimes make a slight change in ingredients that will cause a reaction. Food allergies can appear at any age, in any breed and in both males and females whether or not they have been altered.


The most common allergens in dog food include:

  • Beef
  • Dairy products
  • Chicken
  • Lamb
  • Wheat
  • Eggs
  • Corn
  • Soy
  • Whey

Food allergies are sometimes caused by the chemicals in the food rather than the food itself. Preservatives and pesticides in food are known to cause allergic reactions. The process that occurs within dogs that creates allergies is complicated and not fully understood at this time. It is known that when a substance is fed to dogs regularly for a long period of time, allergic reactions to that substance may begin to develop.

Lamb-based foods were originally created as an alternative for pets with dog food allergies but have become common and now produce allergic reactions of their own. It is a common and unfortunate myth that dogs should eat the same thing everyday throughout their lives. In addition to providing more complete nutrition and food enjoyment, feeding a wide variety of foods can help prevent the development of allergies and sensitivities.

Diagnosing Dog Allergies

Food allergies can difficult to distinguish from other health problems and other types of allergies, but there are some signs to look for. Likely candidates for food allergies are dogs who experience symptoms year round rather than seasonally, dogs who do not respond to antihistamines or steroid treatment, dogs who develop skin problems at a very young age and those who have recurrent ear problems. Allergy tests are available for dogs.

The best way to find the source of the allergy or sensitivity is an elimination diet. This involves replacing all of the foods the dog normally eats for a long enough period of time for the symptoms to subside and then reintroducing the foods one at a time until the symptoms reappear. A diet consisting of duck and potato is the most commonly recommended elimination diet to begin with. Elimination diets take time to produce any results. The offending substances must work their way out, and the dog's system must recover and stop producing the antibodies that cause the symptoms. This can take anywhere from six to ten weeks. When the original food items are reintroduced, it can take two weeks for symptoms to reappear.

Best Allergy Free Dog Food

For dogs with food allergies, elimination diets remove the symptoms, but are not always nutritionally complete and, therefore, should not be fed long term. A specially tailored home-prepared diet is the best option for dogs with food allergies. For those who cannot, or prefer not to feed a home-prepared diet, the wide variety of dog foods on the market today provide a vast selection of alternatives. A careful reading of the ingredients combined with close observation after feeding for at least one to two months will determine whether the food is appropriate and allergen free.

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Overview of Dog Food Allergies and Symptoms