Canine Food Allergy

"Canine food allergy (food hypersensitivity) occurs when a dogs immune system reacts to an ingredient in a dogs diet. Affected dogs tend to be younger (under 1 year) with no predisposition based on heredity with the exception of the Soft Coated Wheaten Terrier. It can cause symptoms such as itch (pruritis),skin rash (seborrhoea) and gastrointestinal problems such as diarrhea. Treatment involves the use of an elimination diet where the diet is reduced to a simple carbohydrate and protein. This diet is fed to the dog for a minimum of 6 weeks (avoid all other foods such as treats). If the dog improves, the diet is continued for another 4 weeks. Foods are gradually added back in to determine which ingredient is the cause of the allergy."

Canine Food allergy problems in dogs are less common than allergies to allergens in the air (atopy) such as pollen.

Food allergies are seldom from hormones, additives or preservatives. They are usually due to a natural food product such as meat, milk, eggs, fish, beef, pork, horse meat, grains, potatoes, soy or additives. Of these the most common ingredients are beef, chicken, corn and diary. 

Switching to organic food will not help since all of these are the same in their organic form. It is not unusual for a dog to develop an allergic reaction to a food they have been eating for several years.

canine food allergy
Picture Canine Food Allergy in Dog Eye

Canine Food Allergy Symptoms

If you dog is allergic to food, symptoms usually are non-seasonal, occur within 24 to 72 hours, but can happen in up to 2 weeks. Like other allergies, you will see your dog itch frequently, see small red skin bumps or raised areas of skin. You will usually see the allergic rash on the belly, back of the legs, ears and feet.

Symptoms appear similar to flea allergy and canine atopy (allergic reaction to pollen, foods etc.).

canine food allergy
Picture Canine Food Allergy on Dog Face

canine food allergy
Picture Dog Food Allergy on Dog Rear

Treatment and Diagnosis of Canine Food Allergy

The key to diagnosing a food allergy is to eliminate as many foods as possible and then see if the allergic reaction disappears. Your Veterinarian will put your dog on a diet that consists of as few ingredients as possible (called hypoallergenic canine diet). Just switching dog foods doesn’t work as each has too many ingredients. Also, antihistamines and allergy shots tend not to work.  Treatment will also be initiated to address any symptoms.

It takes as many as 10 weeks to see if a test diet is working. Recent studies have shown that a diet prepared at home is the best course of action. If this isn’t practical, consider simple combination dog food such as Hill’s salmon/rice or duck/potato. It is suggested that when testing different foods, your dog should only drink water.

To help the skin heal, therapies such as the use of steroids may be needed, although this approach doesn't always work.  Antibiotics can be helpful (neomycin) and are applied as a powder or ointment.  Skin therapies are tested first to determine if the dog is sensitive to the medications. A homeopathic product such as Allergy Itch Ease can help to reduce symptoms such as rash and itch.

Your dog may not like the change, but be careful with the temptation to also provide a treat since the treat itself could be the cause. One substitute for treats is fruit since fruit rarely is the cause of allergic reaction.

Once you find something that works, stay with it.


Brevitz, Betsy, DVM; Hound Health Handbook

Greek, Jean, DVM, ACIDM; New Hope Animal Hospital “Atopic Disease and Allergy”

Beale, Karin M. DVM, Gulf Coast Veterinary Specialists – “Atopic Dermatitis: Clinical Signs and Diagnosis”

Giffin, James M. MD & Carlson, Liisa D., DVM “Dog Owner’s Home Veterinary Handbook”.

Lloyd, Professor David, Royal Veterinary College, Hawkshead Campus: “Diagnosis & Management of Adverse Food Reactions in Dogs”

Osborn, Sarah Colombini DVM, Southwest Veterinary College, Houston: “Optimal use of Hypoallergenic Diets”

Ihrke, VMD, Professor of Dermatology, School of Veterinary Meicine, University of California: “Flea Allergy Dermatitis”

Diagnosing, Treating and Preventing Food Allergy
Richard EW Halliwell, MA VetMB PhD MRCVS DECVD
Professor, University of Edinburgh, Royal (Dick) School of Veterinary Studies, Summerhall, Edinburgh, UK


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