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Food Allergies in Dogs

Causes, Symptoms, and Treatment

dog food allergies
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Food allergies in dogs are uncommon and may cause problems with the skin, ears, or gastrointestinal tract. Usually, a dog food allergy will appear suddenly after prolonged exposure to a food allergen. Symptoms vary in severity and often overlap with other conditions, so see your veterinarian to narrow down the possible causes. Here's how to tell if your dog has food allergies and what to do about them.

What Are Food Allergies?

Food allergies occur when the body's immune system identifies a substance as an invasive threat to the body that must be attacked. The immune response causes inflammation in the body.

Dog food allergies tend to occur suddenly after prolonged exposure to a specific ingredient in dog food, often a protein. Many dogs develop food allergies after eating the same food for a long time.

Symptoms of Food Allergies in Dogs

Food allergies often develop in puppies under 6 months old or adult dogs over age 5. The symptoms of food allergies in dogs can easily be misattributed to other conditions, so if you're not sure why your dog is experiencing discomfort, a trip to the veterinarian is best.

Skin Issues

Dogs with food allergies typically experience skin issues like itching, redness, rashes, raw spots, flaking, crusty lesions, and hair loss. The allergic reaction will likely occur between six and twenty-four hours after ingestion. This is in response to the inflammation caused by the allergen.

Chronic Ear Infections

Many dogs with food allergies will have chronic ear infections. These may accompany skin issues or occur separately.

Gastrointestinal Issues

Gastrointestinal problems like vomiting and diarrhea may occur alongside skin issues. Less commonly, GI problems may occur independently, but this may be considered a food intolerance rather than an allergy.

Behavioral Changes

Some dogs will experience behavioral changes due to repeated exposure to an allergen. These changes may include hyperactivity, lethargy, or anxiety due to the stress of constant discomfort.

What Causes Dog Food Allergies?

The source of food allergies in dogs can be any ingredient that causes an inappropriate immune response. Common allergens are proteins, such as chicken, beef, egg, dairy, or soy. Food allergies sometimes stem from genetic predisposition or environmental exposure early in life.

How Vets Diagnose Food Allergies in Dogs

Before diagnosing a dog with food allergies, your veterinarian will rule out other causes of skin problems. They'll conduct a complete physical examination and look for specific signs that point to food allergies.

Your dog must be flea-free to ensure the skin problems are unrelated to flea bites. This requires the use of effective flea control methods all year long. Your vet can help you find the right product for your dog.

Your vet may want to rule out environmental allergies by treating them with antihistamines and anti-itch medications. If there are skin or ear infection signs, your vet will likely treat your dog with antibiotics or topical ear medications.

Although allergy testing is available, most veterinarians agree that these tests are not accurate enough to properly diagnose dog food allergies.

How to Treat Food Allergies in Dogs

Food allergies are not curable, but you can manage them with a special diet. Your dog's food allergy will not go away, so treatment is necessary to relieve your dog of pain and discomfort.

The first step to treating a food allergy in dogs is discovering what ingredient is causing the allergic reaction. The best way to do this is by feeding a special diet to your dog for about eight to twelve weeks.

A food trial for dog food allergies aims to eliminate as many potential allergens as possible from the diet. It generally involves feeding a novel protein (something new to the dog that has never been fed before) or a diet made with hydrolyzed protein. Your vet can help you choose a high-quality diet made with the necessary ingredients.

Novel Protein Diets for Dogs

Novel protein diets are generally composed of one uncommon protein source (like venison, kangaroo, duck, or rabbit) and one carbohydrate source, plus necessary vitamins, minerals, and nutrients to make the dog food complete and balanced. Let your vet help you select a diet you can trust only to contain the listed ingredients. Some commercial limited-ingredient diets will contain traces of other ingredients due to cross-contamination at the processing facility.

Hydrolyzed Protein Diets for Dogs

These diets contain hydrolyzed proteins, which have been broken down so that the immune system will not recognize them as the same ingredient.

Once a dog food has been chosen, your veterinarian will instruct you on conducting a proper dog food trial.

Strict Food Trials

The most important rule of a food trial is to feed only the limited ingredient diet for the period recommended by your vet, usually eight to twelve weeks.

  • Do not feed any other foods or treats unless they contain these exact ingredients.
  • Be sure everyone in your home is aware of the rules.
  • In most cases, it's best to feed all dogs in the house the same food or separate pets while eating.
  • Keep other foods, like cat and human food, entirely out of reach.
  • Your dog's skin problems may begin improving early in the trial period. Report these results to your vet, but do not stop or alter the food trial unless instructed by your vet.

Your vet will assess the outcome at the end of the recommended trial period. If your dog's signs improve, they may recommend gradually adding additional protein ingredients to your dog's diet, usually one at a time for a couple of weeks. This can help determine what foods your dog can and cannot tolerate.

Some dogs must remain on special diets indefinitely to control allergies. However, you may find that your dog is only allergic to one or two proteins and can eat all others without reactions. Again, work closely with your vet to choose the right dog food and manage your dog's allergies. Be sure to visit the vet for routine wellness exams every six to twelve months or as your vet recommends.

Prognosis for Dogs With Food Allergies

You cannot cure your dog's food allergies, they can be managed with specialized treatments and diet. Once the allergen is identified, the best treatment is total avoidance. Exposure to an allergen can easily cause a relapse, so vigilance is essential when feeding your dog new foods. If your dog has one allergy, more may develop over time.

How to Prevent Food Allergies

Due to unpredictable genetic factors, food allergies in dogs aren't preventable altogether. If you begin your dog on a hypoallergenic diet beginning at puppyhood, allergic reactions may be avoidable but not preventable.

FAQ
  • What is the best way to treat my dog's food allergy?

    There are several ways that a dog's food allergy can be treated or made less severe, such as very slowly reintroducing an allergen into your dog's diet. But the best treatment for a dog's food allergy is complete avoidance of the allergen and finding the proper diet to accommodate your dog's needs.

  • How do I know if my dog has food allergies?

    The symptoms of a dog's allergic reaction to food can be similar to that of a skin condition. Before diagnosing a dog with food allergies, your vet will rule out various forms of dermatitis and the presence of fleas. Following that, Your vet will conduct a full physical examination, and tests will be done to find the specific food allergens. 

  • How do I prevent my dog from developing food allergies?

    Unfortunately, genetics is largely at play in your dog developing a food allergy. Prevention isn't entirely possible, but you can feed your dog a hypoallergenic diet starting in puppyhood.