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Animal Skin and Allergy Clinic Blog

Pet Food Allergies and Diet Trials: All You Need to Know

A shaggy brown and white dog at a bowlHaving an itchy pet is frustrating. The solution requires determining not only the source of your pet’s itching, but also the best strategy for managing whatever your pet’s condition may be.

Investigating the cause of your pet’s itching may include checking for a food allergy. But how do you know if your pet needs to be checked for food allergies, and what exactly is involved?

How Do I Know if My Pet Might Have a Food Allergy?

A pet food allergy is a response by the body to a food that has been ingested. These reactions can be due to a chemical or other intolerance, not necessarily allergy, so it is more accurate to call these adverse food reactions. Many times the offending food item is a protein. Occasionally, though, a carbohydrate can be the cause of the issue. In order from most common to least, the causes of adverse food reactions in dogs and cats include:

  • Beef – most common
  • Chicken
  • Soy products
  • Dairy products
  • Eggs
  • Fish
  • Wheat gluten
  • Corn – least common

Pets who have food reactions may develop hives or be itchy and chew or lick their paws, sides, groin, neck, or ears. In some cases stomach or intestinal signs may manifested, such as vomiting, frequent stools, or diarrhea. Except for the gastrointestinal signs, these can also be symptoms of other allergies and skin conditions, making food reactions difficult to diagnose based on physical signs alone.

How Are Pet Food Reactions Diagnosed?

Unfortunately there is no simple lab test we can use to diagnose a food reaction in your pet. Blood tests, while available, are inaccurate in assessing the cause of a potential food reaction.

When an adverse food reaction is suspected, a feeding trial is generally conducted as the best means of rooting out the cause. During a feeding trial, your pet is fed a special elimination diet for a period of 4-8 weeks. The food elimination diet usually contains a new, highly digestible protein source with minimal additives. These contain a novel protein and carbohydrate that the animal has never been fed before. These diets are often called a limited ingredient diet (LID).

During an adverse food reaction feeding trial, the pet:

  • Is only fed the prescribed diet
  • Cannot receive treats or table scraps
  • Should only receive non-flavored medications
  • Needs to be prevented from gaining access to other food sources such as in the yard, garbage, or from other pets and people

If your pet’s skin problems totally resolve or improve significantly during the feeding trial this indicates a positive test result. To prove that this is a true positive you should feed your pet his or her old diet in order to check for the return of previous symptoms. If that occurs, a diagnosis of an adverse food reaction is confirmed.

How Are Pet Food Reactions Treated?

Once an adverse food reaction has been diagnosed, treatment is relatively simple. The animal must not be exposed to the offending ingredient in the future to avoid clinical signs. Most times we are able to identify “safe” food ingredients these pets can eat that do not trigger an allergic response. The Animal Skin & Allergy Clinic has prescription pet food and treats available that are made specifically to address adverse food reactions, so are lacking the common ingredients that cause these reactions.

When your pet is being put on a prescription diet you may wonder about something that is known as a “grain free” diet. This is a term coined by over the counter pet food companies, but in actuality these diets have no scientific basis as a treatment for adverse food reaction in pets. It is usually a protein (beef or chicken) that is the most common offending ingredient, while grains (wheat or corn) are the least common reason for adverse food reactions. You will get much farther by eliminating everything your pet is currently eating and feeding a completely novel diet.

Dealing with allergies in pets can be challenging, though getting a diagnosis of adverse food reaction can make it easier to deal with. Ruling food reactions in or out as a cause of a pet’s skin problems is an important step in assuring your pet is more comfortable.