Food allergies are not as common as pet food companies claim, but they can be problematic for your furry pal by causing extreme itchiness, skin lesions, secondary infections, and potentially gastrointestinal (GI) distress. Our Peak Pet Urgent Care team wants your pet to enjoy a pleasant dining experience, and we provide information about food allergies in pets.

What is a pet food allergy?

When your pet has a food allergy, their immune system recognizes an ingredient in the food as foreign and their body produces antibodies to attack that substance. The resulting inflammation typically targets the skin and/or GI tract. Pets are often on the causative diet for many months or years before a food allergy develops, since the body needs time to produce antibodies.

What causes pet food allergies?

Pet food allergies are most commonly caused by a protein in the pet’s food, but other ingredients, such as wheat and food additives, can also trigger a reaction. Common pet food allergy culprits include:

  • Chicken
  • Beef
  • Dairy
  • Soy
  • Eggs

What are pet food allergy signs?

Pet food allergies can cause dermatologic and/or GI signs, such as:

  • Excessive itching — Affected pets may lick, chew, scratch, and rub constantly. Dogs are commonly affected on their face, feet, and anal area, while cats are most often affected on their face and neck.
  • Skin lesions — Your pet’s chewing and scratching can cause inflammation and trauma that lead to hair loss, redness, and abrasions. Cats may also develop crusty lesions, papules, and plaques. 
  • Recurring or chronic ear and skin infections — Pets with food allergies often also suffer with chronic or recurrent ear and skin infections.
  • Gastrointestinal signs — Approximately 30% of pets with a food allergy experience vomiting and diarrhea.
  • Weight loss — Affected pets may lose weight, especially if they have GI signs.

How is a pet food allergy diagnosed?

Itchy skin is a common problem in pets that numerous issues, such as flea-bite dermatitis, atopy, or food allergies, can cause. This means that a prolonged diagnostic process may be necessary to rule out other potential causes. Diagnostic steps may include:

  • Physical examination — In some cases, the location of your pet’s skin lesions can help suggest the causative allergen. For example, pets who have a flea-bite sensitivity often have lesions on their lower back, abdomen, and inner thighs.
  • Flea prevention medication — Although uncommon in our region, flea-bite sensitivity is the most common pet allergy, and the condition can also complicate other allergy types. Your veterinarian will ensure your pet is protected against these parasites.
  • Diet trial — A food allergy can be definitively diagnosed only through a diet trial. 

What is a pet diet trial?

A diet trial involves feeding your pet a diet with a hydrolyzed or novel protein source for about eight weeks to see if their signs improve. Considerations include:

  • Your pet must eat only the trial diet during the eight-week period, which means no flavored chewable medications, rawhides, food scavenged from the garbage, or unsanctioned treats.
  • Everyone in your family must participate to ensure your pet doesn’t receive food outside the trial.
  • Other household pets should be separated at meal times or should also eat the diet trial to prevent food-sharing problems.
  • If your pet responds well to the trial diet, they are challenged with their original diet for two weeks to see if signs return. If signs return, a food allergy is diagnosed.
  • Once your pet’s signs are under control on the special diet, you can challenge them with individual ingredients from their original diet to determine the ingredient causing the problem.
  • The causative ingredient, once identified, should be eliminated from your pet’s diet forever.

What diets are appropriate for a pet diet trial?

Diet options for a pet diet trial include:

  • Novel protein diet — These diets contain a novel protein, such as kangaroo, venison, or duck, that your pet has never eaten. 
  • Hydrolyzed protein diet — The protein in these foods has been broken down into small molecules that the immune system doesn’t recognize. 

What about allergy testing to diagnose pet food allergies?

Allergy testing, such as radioallergosorbent testing (RAST) and intradermal testing, cannot identify food allergies in pets. These tests are meant to help identify what environmental allergens trigger signs in atopic pets so a hyposensitization therapy can be formulated.

How are pet food allergies treated?

The best way to address a pet’s food allergy is to determine and eliminate the causative ingredient from your four-legged friend’s diet. Other necessary treatments may include:

  • Flea control — Food allergic pets often also are sensitive to fleas, and if you travel outside our region, your pet should receive year-round flea protection.
  • Anti-inflammatory medications — Medications, such as steroids, may be necessary to control your pet’s itching, especially in the initial phases.
  • Anti-itch medications — Anti-itch medications may also help manage your pet’s food allergy.
  • Antibiotics — If your pet has a secondary skin or ear infection, they will likely need antibiotics to clear the infection.
  • Omega-3 fatty acids — Omega-3 fatty acids help support pets’ healthy skin and may be recommended.

If your pet can’t stop scratching, contact our Peak Pet Urgent Care team, so we can determine the cause and help alleviate the itch.