Dog Allergies Symptoms Caused by Food

Dog allergies symptoms that are caused by food are the third most common type of allergy that affects our canine pets. Allergies to food can show themselves in several ways in and on your dog. Let’s take a look at some of the most common clinical signs of food allergy and what can be done to help your dog feel better.

Signs of Canine Food Allergy

One of the first clues many dog owners have to a potential food-related allergy in their pets is when the dog begins scratching excessively. Other signs of a food-based allergy can include chewing on a foot, leg or tail; rubbing the face or ears; head shaking; persistent ear infections; and hair loss.

Other indications of a possible canine food allergy can include digestive upsets (vomiting or diarrhea), sneezing, wheezing or changes in behavior.

Because many dogs develop an allergic reaction to their food seemingly overnight, the pet’s food is not usually the first thing that’s suspected as causing the problem. Food allergies can develop in any breed of dog at any time in the pet’s life, so be sure to consider the possibility that your dog’s food may be the cause if he develops any of these clinical signs.

How Food Allergies Develop

Your dog’s immune system causes his food allergy. When his body has eaten enough of a particular food to cause an allergic reaction, your dog’s immune system overreacts to try to fight off the allergen by creating the chemical histamine. It causes your dog’s skin to become inflamed and itchy, and hives to form. Histamine may also cause a reaction in your dog’s digestive tract, leading to vomiting and diarrhea.

The most common causes of canine food allergy include beef, dairy products, chicken, fish, eggs, soy, wheat and corn. Although preservatives and other chemicals have been implicated in the past as possible allergens, more research is required to prove or disprove this implication.

Sometimes It's a Food Intolerance

In some cases, your dog may not have a food allergy, but rather a food intolerance. Food intolerance affects up to half of all pet dogs, but it’s less well-known than food allergy, which affects only about 10 percent of pet dogs.

Food intolerance causes a problem for affected dogs within an hour of eating. It can be caused by an inability to digest ingredients in the diet that range from fats to artificial colors. Affected dogs will suffer digestive upsets (vomiting, diarrhea, flatulence) until their diets are changed. If left untreated, a food-intolerant dog may develop hair loss and itchy skin because he is unable to obtain proper nutrient levels from his food.

Diagnosing a Food Allergy or Intolerance

If your veterinarian suspects your dog has a food allergy or is food intolerant, he or she will place the dog on what’s called an exclusion diet. This diet will feature new protein and carbohydrate sources that your dog has never eaten before. Examples of exclusion diets include venison and sweet potato or duck and potato.

Your dog will need to eat the diet for several weeks while your veterinarian evaluates his condition. It’s important not to supplement the exclusion diet at all during the trial period because your veterinarian needs to know the ingredients of your dog’s diet in order to evaluate his health and make recommendations for the next steps of care.