Your dog is obviously uncomfortable鈥攔epeatedly licking their feet, rubbing their face, scratching their belly, and shaking their head鈥攁nd you can鈥檛 figure out the cause. You鈥檝e checked for fleas, haven鈥檛 used fertilizer on your lawn or switched laundry detergents, and you鈥檝e fed the same high-quality dog food for years.
Clearly, it鈥檚 time to make an appointment with your veterinarian. A food allergy is one of the conditions that could stimulate these afflictions, but it鈥檚 difficult to determine and requires diagnosis by an expert.
What Is a Food Allergy?
Canine food allergies, also called cutaneous adverse food reaction (CAFR), evoke a strong immune response to specific food ingredients, usually proteins or carbohydrates. Food allergies usually develop in young dogs but can begin at any age. And what鈥檚 tricky is a food allergy develops over time, so a dog can eat the same food for years before having a reaction.
Dr. Barbara Feinstein, veterinarian and partner at the , says she is seeing an increase in patients with food allergies. Research shows that food allergy is diagnosed in up to one-fourth of dogs exhibiting allergic skin reactions. 鈥淢aybe we鈥檙e more attuned to it, or maybe it鈥檚 because dog foods contain ingredients they never did in the past,鈥� conjectures Dr. Feinstein.
Symptoms of Food Allergies
Symptoms of a food allergy include very itchy feet, abdomen, face, and anal area that causes the dog to scratch, chew, lick, and rub themselves. As a result, they often develop skin lesions, bacterial infections, or yeast infections. Ear infections occur in about 50% of dogs with food allergies and sometimes are the only symptom. About 30% of dogs also may suffer from diarrhea or vomiting, especially puppies. In rare cases, bronchitis or anaphylaxis occur.
鈥淒ogs with a food allergy often suffer from other allergies, for example to mold, pollen, dust mites or insect bites,鈥� says Dr. Feinstein. 鈥淲hatever is causing your dog鈥檚 discomfort needs to be addressed as soon as possible by a veterinarian to determine the cause, relieve the symptoms, and prevent secondary infections.鈥�
Diagnosing Is Difficult
When Dr. Feinstein sees a patient with these symptoms, she rules out a series of potential causes. 鈥淔irst, I look for signs of external parasites, such as fleas or ticks, and for ringworm, which may involve looking at skin scrapings or cultures. Blood tests can rule out Cushing鈥檚 Disease or hypothyroidism and ringworm. I talk to the owner about any changes in the dog鈥檚 environment to rule out contact dermatitis. I ask whether the irritations are seasonal, and whether anyone else in the family has lesions because ringworm and mites can affect humans.鈥�
Dr. Feinstein will also check on the dog鈥檚 diet, including treats and table scraps, to consider a food sensitivity. Food sensitivity is a chronic condition rather than an immunological response to a specific ingredient. For example, a dog may react with diarrhea and vomiting to foods with high-fat content. Some veterinarians don鈥檛 differentiate between food sensitivities and allergies because in both cases a change in diet is required to relieve the symptoms.
While it may seem like an overwhelming task, owners should also read the ingredients list before purchasing dog food. Owners should at least look at the first four ingredients of the diet they choose to feed their dog. It鈥檚 always best to check with your veterinarian for recommendations before making a change in your dog鈥檚 diet.聽
Prepare to Help Your Veterinarian
It鈥檚 important for your veterinarian to have one consistent contact during this process. That person should prepare to answer the following questions:
- What are you feeding your dog, and how long have you fed this food?
- What treats, medications, and table scraps does your dog eat?
- Where and how is dog food stored?
- Is your dog on any flea and tick preventatives?
- If other pets live in your house, what do they eat?
- Have you made any changes to the dog鈥檚 environment?
- When did the dog鈥檚 itching start and does it get worse during specific seasons?
- Is anyone else in the house itching?
Common Allergens and Who鈥檚 Susceptible
鈥�Chicken was historically believed to be the protein most likely to cause food allergy, but today we find allergens to include beef, dairy, wheat, and lamb,鈥� reports Dr. Feinstein. Studies also show canine allergic reactions to soybean, eggs, corn, and walnuts.
Certain breeds may be predisposed to having a food allergy. These include the Boxer, Labrador Retriever, Pug, Rhodesian Ridgeback, and West Highland White Terrier. The German Shepherd Dog and Golden Retriever also have a higher rate of food allergies.
What Can You Do to Relieve Food Allergies?
There is no cure for food allergies, so it鈥檚 important to identify the allergen and eliminate it from the dog鈥檚 diet. The only way to reliably pinpoint the cause of a food allergy is with an elimination diet. Your veterinarian can relieve the symptoms by prescribing anti-inflammatory medications, such as Cytopoint, Apoquel, or prednisone.
There are two types of elimination diet. Novel protein diets contain only one protein and one carbohydrate with a minimum number of additives, and they avoid ingredients in the dog鈥檚 previous food. Novel protein diets should not include ingredients capable of with proteins in the dog鈥檚 previous diet, such as lamb, beef, and milk or chicken, whitefish, and salmon. The hydrolyzed protein diet includes a protein that is broken down into small bits easier to digest. However, the dog can still experience an allergic reaction to these proteins.
Dr. Feinstein prefers using a prescription novel protein diet provided by the veterinarian. 鈥淭hese foods are much more palatable than they used to be.鈥� Some veterinarians recommend a single-protein diet so that it鈥檚 easier to understand exactly what you鈥檙e feeding their dogs. You should know not only the brand, but also the protein content of your dog鈥檚 food. But they can be contaminated with other proteins from foods manufactured in the same place or may have unlabeled ingredients.
Home-cooked diets with ingredients specified by your veterinarian can work if they鈥檙e balanced and meet . It can be difficult to provide a proper nutritional balance on your own, especially if you鈥檙e feeding a young large-breed dog.
Elimination Diet Rules
To identify food allergies in , elimination diet trials should last at least 8 weeks. Dr. Feinstein suggests 12 weeks, so the diet can span two seasons and eliminate seasonal allergies as the cause of irritations. Some veterinarians will conduct a challenge phase when other ingredients are added one at a time to try to identify the specific foods causing the allergic reaction.
These diets require strict management with all family members on board. Dog owners need to eliminate all food items except the prescription food, including treats, table scraps, rawhide chews, oral medications and preventatives, pill pockets, dental chews, flavored toothpaste, even flavored toys. If there are other animals in the house, they must be fed separately and can鈥檛 share water dishes.
If the new diet works, Dr. Feinstein recommends the dog continue eating that food. 鈥淒ogs won鈥檛 grow out of an allergy, so in my mind there鈥檚 no point in reintroducing food we think gave them an allergic reaction. Even if the new food is more expensive than your old food, what you spend on visits and medication to treat allergies adds up 鈥� and your dog is still miserable. Once you find food that keeps your dog healthy and meets their needs, stay with it.鈥�