When it comes to animal wellness, skin irritation is an unfortunate constant in the life of most dogs. Just like with humans, there is a multitude of external stimuli that could cause potential skin irritation. Most commonly, skin problems are related to an allergic reaction that manifests as an unpleasant and uncomfortable irritation. With the proper knowledge of these skin conditions, which are often the result of an allergy, they can be correctly identified and diagnosed. Whether the allergic reaction is brought on by food or the environment, skin ailments are often treatable and preventable with the right care and the right pet shampoo. This article will address and identify the signs and symptoms of dog skin allergies to help you determine if your dog is experiencing the discomfort of an aversion related condition.

What is an allergy?

Simply put, an allergy is an immune system reaction to an external stimulant. When a foreign substance enters the body, the immune system interacts with that substance and reacts appropriately to keep the body healthy. An allergy is the result of an overreaction by the immune system typically manifested in some kind of physical irritation.  

While allergies may seem to come on all of a sudden, they are actually the result of a long period of exposure to a particular stimulant, which is also known as an allergen. Long-term exposure to a specific allergen causes the immune system distress, and it begins to flag the allergen as a threat. The immune system then triggers a response in the form of an allergic reaction, as it tries to eradicate the allergen from the body.  

Can dogs can develop allergies over time?

As addressed in the explanation of what an allergy is, it is relatively common for a dog to develop an allergy to something as they grow older. As your dog’s immune system is repeatedly bombarded by the same stimulant, it begins to produce antibodies to protect itself from potential long term illness. These antibodies are built up over time and develop into allergies as your dog ages. Typically, allergies brought on by external stimuli will begin to manifest after your dog has reached adulthood but could start showing up in your dog as early as sixth months old.  In some rare cases, it may take longer for an allergy to become a problem, and it is not uncommon for dogs to develop allergies late into their adult lives

What are dogs allergic to?

For the most part, dogs are allergic to environmental stimuli. The most common allergens that a dog is susceptible to developing an aversion to are:

  • Heat 
  • Grass
  • Pollen
  • Dust Mites
  • Mold Spores
  • Food
  • Bug Bites

What are the symptoms of dog skin allergies?

Medically speaking a skin allergy is known as allergic dermatitis, which refers to the inflammation or irritation of the dermis, aka the skin. Symptoms will differ depending on the severity and classification of the allergy, but for the most part skin allergies can be identified by one or more of the following symptoms:


Excessive licking – especially in the paws and feet

Itchy ears – shaking his head back and forth

Biting, gnawing at the skin

Excessive chewing

Hair Loss

Red, inflamed skin

Visible rashes

Hives and other bumps 

Swollen face and paws 

How are allergens introduced into my dog’s immune system?

There are three main points of entry for an allergen.  An allergen can be introduced through breathing, eating, and direct skin contact.  There are four main categories in which all of the different allergens fit. Regarding the different types of allergens that a dog could potentially be vulnerable to, allergens can most often be classified as a member of one of these four groups:  

Inhaled – These are allergens that your dog breathes in.  Entering in through the bronchial passages, examples of these types of allergens include dust mites, mold spores, pollen, and dander.  This list of inhalants are just as prevalent in dogs as they are in humans, and believe it or not, your dog can be allergic to the dander of other types of animals.  While inhalants often manifest themselves in the form of respiratory symptoms in humans, in dogs, they are more commonly presented as some form of skin rash or other condition.

Inhaled allergens are, for the most part, seasonal.  As different strains of pollen bloom in the spring and summer, you may notice your dog exhibiting signs of an allergic reaction as a result of seasonal allergies. Typical treatments for skin allergies as a result of inhaled allergens range from dog-safe antihistamines to special formulated anti-itch shampoo.    

Ingested –  This is an allergen that your dog consumes. Typically these allergens come from a food source but could be the result of your dog eating or drinking something outside of their regular diet that you are unaware of.  Maybe your dog gets into the toilet bowl or eats a specific plant while you are on your walk without you knowing. Monitoring what your dog consumes is an integral part of fighting against skin allergies in your dog.

Ingested allergens will often produce the same types of symptoms as inhaled allergens with the potential to exhibit additional severity. Typically food allergies will be the type of allergen that causes your dog swelling in the face, ears, and mouth.  A skin related food allergy often exhibits itself in the extremities, i.e., the paws and feet. If your dog show symptoms of a skin allergy like licking his paws or irritation in the skin flaps of the ears, consider a food allergy as the potential culprit.

Implanted –  This type of allergen refers to any kind of substance that enters your dog from a third party. Fleas and ticks are the biggest culprits of spreading implanted allergens. An implanted allergen is any substance that enters your dog’s bloodstream as a byproduct of another source. For example, when a flea bites your dog, their saliva gets into your dog’s blood, and subsequently, your dog’s immune system is introduced to an implanted allergen.   

Implanted allergens carry with them the most severe forms of skin symptoms.  Typically allergies developed from implanted allergens like bug bites will show up in the form of hives, rashes, and inflamed skin. You may need to separate your dog’s fur to correctly identify this type of allergen. Usually, dogs experiencing an itchy rash like hives will exhibit behaviors like gnawing and aggressive itching. These signs should be taken as cues for an owner to check your dog’s skin below the fur to identify any skin irritation that may be affecting the dermis.

Contact – Contact allergies are, as they sound, the result of an irritant making direct contact with your dog’s body and skin. The allergens most commonly associated with this type of classification include fertilizers, pesticides, household chemicals, and even over the counter dog specific topical medicines.  Sometimes it is hard to remember that your dog’s skin is vulnerable because it is covered with fur. However, your dog’s coat, as much as it is a deterrent from allergens reaching the surface, is also very good at trapping irritants below the fur causing prolonged exposure to the skin.  

While it may come as no surprise that chemicals like fertilizers and household cleaners may cause skin irritation, over the counter dog-specific topical treatments may be a surprise as a potential allergen. It is important to remember that the sensitivity of each dog’s skin is going to be different based on genetics, environment, and overall health. What may have worked on another dog in the past, or for most dogs you know, could be making your dog’s skin condition worse.  

For the most part, contact allergies develop on the skin more rapidly than those types of allergies previously mentioned. Additionally, contact allergies tend to be the least common type of skin allergy in dogs. Even still, it is vital to introduce chemicals that come in direct contact with your dog’s skin on a trial basis to ensure that there are no adverse allergic reactions. As a friendly reminder, try to buy household products that are made with pet-friendly materials to avoid potential contact with allergy triggers. 

Can skin allergies be inherited?

Unfortunately for dogs, allergies can be passed down through genetic material.  Inherited allergies are more common in purebred dogs than they are in mixed breeds, but all dogs can be at risk for inheriting allergies from their parents. Often genetic traits like allergies are passed down in purebreds because there is not enough genetic variance to eradicate the allergic predisposition from one generation to the next. Inherited allergies tend to be of the inhalant category, and are usually seasonal in nature.  

Is heat rash an allergy?

Heat rash is most certainly a type of allergic reaction. While it is not categorized in one of the classifications above, heat is an external stimulant that induces an immune response from your dog. As a result, heat rash can be classified as a type of allergic dermatitis.  

Usually, a dog with heat rash will exhibit the same types of symptoms as other skin allergies, including, irritated skin, excessive itching, and biting or gnawing. Heat rash can be treated with many of the same solutions as other allergies, like regular bathing and medication. 

Unlike other skin allergies, a fastidious grooming routine can make all the difference in treating heat rash.  Especially if you are the proud owner of a long haired dog in a hot and humid climate, grooming your dog’s fur is a must to keep your dog comfortable and allergy free. There are plenty of stylish ways to make your dog look good with short hair, so be sure to stay ahead of heat rash and remove any excess fur that could potentially cause heat-induced skin irritation. 

New environments bring new allergic potential

If you recently moved to a new area, whether it is across the country or to a neighboring county, there are very likely going to be new allergens to deal with. Each microclimate that your dog encounters offer a new potential host of allergic material that your dog must adapt to.  Maybe it is a new strain of pollen that didn’t bloom at your last house or a new type of grass that your dog isn’t used to. Maybe you moved somewhere that is five degrees hotter on average and need tips for caring for your dog in warmer weather.  While five degrees may not seem like a big difference to you, that increase in temperature could be the tipping point that causes your dog to develop an allergic rash due to overheating. New environments contain new allergens that your dog could be potentially susceptible to, and it is important to monitor your dog if and when you make a change to their environment.

How do I determine what kind of skin allergy my dog has?

While you may be tempted to make a rash decision (pun intended) about how to treat your dog’s skin allergy, it is crucial that you seek professional medical advice of your dog’s veterinarian.  Based on your dog’s symptoms, and a working knowledge of his personal medical history, a vet, will be able to accurately determine what is causing your dog’s skin allergy and provide a professional diagnosis. Your dog may show symptoms of allergies or sensitive skin conditions that are not serious, or that require long-term treatment. Your job as a dog owner is to identify when your dog is showing signs of irritation, and symptoms of unusual behavior, and use that information as a springboard to seek help for your dog. The signs and symptoms of dog skin allergies listed above are an excellent guide to help you identify if your dog is struggling, but always seek the counsel of an educated medical professional before testing medications or taking action regarding your dog’s long term health.  

Final Thoughts

Skin allergies in dogs are very common, and they can be easy to spot if you know what you are looking for. Make yourself aware of the most common types of skin problems for dogs. If your dog exhibits any of the signs and symptoms of skin allergies, do your best to take account of any changes in your dog’s environment. Stay vigilant and attentive to the health and condition of your dog’s skin, and if any signs or symptoms of skin allergies develop consult your vet immediately.  







Dr. Melinda J. Mayfield-Davis, DVM, WCHP-AH, brings over 20 years of experience in veterinary medicine.  She is the Technical Services Veterinarian with Innovacyn, Inc., parent company of Vetericyn Animal Wellness. She received her DVM from Oklahoma State University and now resides in Southeast Kansas with her husband, two children, four dogs, and six horses. Prior to working with Innovacyn, Dr. Mayfield owned and operated the Animal Care Center in Columbus, KS.

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