Where Does It Itch: 3 Common Dog Allergies And How You Might Be Able To Tell Them Apart

Itching is the most common symptom of allergies in dogs.  

There are three common dog allergies.  If your dog is itchy, this article will help you identify the cause.

3 key factors to help diagnose these three common dog allergies are:

  • Where on the body is your dog itchy
  • At what age does the itching begin
  • What time of year is your dog itchy
Where Does It Itch: 3 Common Dog Allergies And How You Might Be Able To Tell Them Apart

Food allergies

Food allergies are a reaction to either the protein or carbohydrate source found in your dog’s food.

Dogs with food allergies are itchy primarily in the face, feet, ears, and rear.   

Food allergies can occur in any age dog. However, they should be at the top of the list if your dog starts itching between 6-12 months of age. Because your dog is constantly exposed to the food, this type of allergy occurs all year round.

Reoccurring ear infections are prevalent in dogs with food allergies.  

Diagnosis involves a food elimination trial—placing your dog on a prescription diet with no other food or treats for 6-8 weeks.  Once diagnosed, treatment is simple and involves strict diet control.

Flea allergy dermatitis (FAD)

Flea allergy dermatitis is the result of the reaction that your dog has to flea saliva.

Dogs with FAD are primarily itchy at the base of their tail.  

Flea allergy dermatitis can occur in any age dog. However, this type of allergy is usually seen only during flea season.

This is the easiest allergy to treat!  A flea eradication program for all dogs that live in the household and treating the environment will resolve the problem.

However, dogs can be itchy for up to one month after the bite of just one flea.  Fortunately, the itching can be relieved by giving your dog steroids prescribed by your veterinarian.

Inhalant allergies (Atopy)

Inhalant allergies, also known as atopy, are caused by environmental allergens such as grass, trees, pollen, and mold.

Dog with atopy are itchy all over their body and not in a specific area like food or flea allergies.  

Symptoms for inhalant allergies usually develop in dogs between 1-3 years of age.

Dogs with atopy are usually itchy only during a portion of the year when the allergen levels are high. Diagnosis is usually made by ruling out the two other types of allergies. However, skin and blood testing can be performed to help determine what your dog is allergic to.

Here is an article I wrote about treatment options for inhalant allergies.


Some dogs can have all three types of allergies, which makes diagnosis and treatment more difficult. 

Generally, dogs with all three allergies are less itchy in the winter. That is particularly true if they are on a diet specifically for their food allergies.

Related articles:
Common Dog Misdiagnoses: Skin Issues
Allergies in Dogs: Common, Commonly Misdiagnosed, or Both?

Categories: AllergiesConditionsDiagnosesDog health advocacyItchingSymptoms

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Dr. Anna M. Coffin, DVM

Dr. Anna Coffin is the owner and veterinarian of Guthrie Pet Hospital. She was born and raised in Guthrie, Oklahoma on an agriculture farm North of Guthrie, where her family of 6 children grew peaches, cherries, apples, strawberries, and asparagus. Her parents raised her with Christian values and an excellent work ethic. Growing up as a child, she had one outside dog that wandered up to the house. Her family was swimming in the creek, and he stole their shoes, so they named him Thief. He became part of their family and lived a good long life. When she was in Jr. High, another stray came along that she became attached to. He was missing for a few days, and she found him on the side of the road dead. He had been hit by a car and left there to die without any help. That was the moment she decided that she was going to become a veterinarian. She graduated from the Oklahoma State University School of Veterinary Medicine in 1994. Upon graduation, she married a veterinary classmate and moved to New Hampshire for three years. She became homesick and in 1997 decided to move back home and purchased Guthrie Pet Hospital. She enjoys practicing medicine and helping over 1500 pets and their parents. In 2009, she went to Baltimore for extensive dental training and enjoys the art of dentistry. Dr. Anna also owns One Stop Copy Shop providing locals customers with copying needs and also has a bed and breakfast called Jaded Getaway. She enjoys spending time with family and friends, reading, and volunteering for Friends of Guthrie Animals and Relay for Life.

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