Allergy Bumps in Dogs: What They Look Like & What to Do [With Pictures]

This article was updated on September 8th, 2023

A dog’s skin is a complicated organ that can be prone to many concerning issues. One of the most common reasons that dogs visit a veterinarian for their skin is allergies. Allergies to food or things in the environment can show up in many ways that can appear similar to other common skin issues. Here we will help you determine if your dog’s skin issues are due to allergies and what you can do to help.

Common causes of allergy bumps in dogs

Just like humans, individual dogs can be allergic to a variety of things, and each individual can react to allergens differently. While determining exactly what your dog is allergic to should involve your dog’s veterinarian (and specialized testing), here are some allergen possibilities:

1. Bumps from environmental allergies: Allergies to pollen, dust mites, mold, or certain chemicals are considered environmental since they’re “in the environment” where your dog exists. Environmental allergies are fairly common and usually lead to itchy bumps on the skin, watery/ itchy eyes, and excessive scratching/ licking. Again, these allergy bumps usually show up on the lighter haired areas of the body.

Environmental allergies are treatable and may in fact resolve entirely if the allergen can be removed (such as a cleaning product that can be replaced with something else.)

2. Bumps form flea or parasite allergies: Flea bites are bad enough, but in some dogs they can trigger an allergic reaction all over the skin. Flea allergy bumps are commonly seen at the base of the tail but can show up anywhere on the body. You may also notice flea dirt or actually see the little bugs jumping when you groom.

External parasite (flea and tick) prevention is important for general health, which is why your dog’s veterinarian may recommend things like regularly administered pills, topical liquids, or collars. These products are especially important for dogs who are allergic to fleas, as flea allergy isn’t curable and can cause incredible discomfort and skin damage leading to infections. Flea allergies are usually recognized by fur loss over the rump, thickened and uncomfortable looking skin, and frequent licking and chewing.

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3. Bumps from insect bite allergies: In addition to fleas, some dogs may have an allergic response to bites or stings from mosquitoes, bees, biting flies, etc. Look for these on the face and legs since those are the parts that dogs use to investigate with. These bumps can cause lots of swelling and redness and can even interfere with breathing.

Some topical products help prevent bites from mosquitos and other flying insects. Your veterinarian may recommend switching to a product labeled for that purpose if your dog has this type of allergy.

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4. Food allergy bumps: This is a specific type of allergic reaction to certain food ingredients. Food allergies in dogs are fairly uncommon. While there’s a widespread misconception that dogs are allergic to grains or carbohydrates, the majority of food allergies are actually due to the protein source. Those that do have food allergies may show gastrointestinal signs (vomiting and diarrhea), while others have skin reactions such as rashes or chronic ear infections.

Food allergies can usually only be successfully managed a specialized diet.

5. Bumps from autoimmune disorders: In very rare cases, immune system dysfunction can cause the body to attack its own tissues, sparking allergy-like reactions to various things or even causing allergy-like reactions to “nothing”. Learn more about autoimmune disorders [with pictures].

What allergy bumps look like in dogs (with Pictures)

Allergy bumps in dogs typically appear as:

• raised, red bumps
• red, hot skin
• welts on the skin
• oozing, weeping
• excessive itching or scratching

Bumps from an allergic reaction can vary in size and may be itchy or painful. They can also show up anywhere on the body but tend to be seen more commonly in lighter haired regions like the belly, groin, face, or between the toes.

This dog has lots of swelling around the eyes and lips as a result of an allergy. Skin may also feel hot and dogs may rub their face on the ground or with their paw.

A dog’s haircoat protects them from many environmental allergens, so you’re more likely to see allergy rashes in the lighter haired areas like the belly, groin, and armpits.

Allergy bumps can also show up between the toes. You may also see dogs licking or chewing their red paws excessively.

If left untreated, allergy bumps can progress to an infected wound when a dog is allowed to lick or chew at the area. These wounds may be red, hot, and have a smelly discharge.

Along with the visual signs, you may also notice your dog scratching or licking, restlessness, or even a decrease in appetite.

Types of allergy bumps in dogs and what it means for your dog

There are a variety of bumps potentially associated with allergic reactions, and they can help you decide how to intervene.

1. Urticaria: Commonly referred to as “hives”, these are raised, itchy bumps that may resolve within a few hours. Urticaria can be a precursor for a more severe allergic reaction known as anaphylaxis. If the hives don’t resolve quickly or with a single dose of oral Benadryl, call your dog’s vet to make an appointment to avoid more serious complications.

2. Papules: These are small, solid bumps that can be red, pink, or flesh-colored. They may not be itchy, and are much smaller than hives. Papules are evidence of mild skin irritation.

3. Pustules: Often compared to pimples, these are pus-filled bumps that may indicate a bacterial infection that’s happening as a result of skin irritation from allergies. Topical or oral medication are often necessary to treat the infection, in addition to treatment for the allergic reaction.

4. Vesicles: These are small, fluid-filled sacs that can burst and crust over. This indicates significant skin inflammation and irritation, and often needs a medication to calm the skin such as a steroid or non-steroid anti-inflammatory medication.

5. Erythema: This is generalized redness or inflammation of the skin, and is the reaction seen most often with flea allergy reactions. The flea bites cause inflammation across wide areas of skin which then become thickened and uncomfortable.

How to distinguish between allergy bumps and other skin conditions

Bumps can form on the skin for a variety of reasons, and even bumps like papules, pustules, vesicles, and erythema may be caused by something other than an allergy. Before attempting to treat your dog for allergies yourself, consider the following:

• Allergy bumps are usually raised and red, often accompanied by itching.
• Other skin conditions like skin infections or injuries might look different, sometimes with scaly patches, flaky skin, or blisters.

It’s important to consult a veterinarian for an accurate diagnosis and a tailored treatment plan.

What owners can do at home

While there are no at-home cures for allergies, there are some basic treatments you can try while you wait for an appointment with your dog’s veterinarian:

1. Keep your dog’s environment clean and act to reduce potential allergens. If your dog suddenly had an allergy-like reaction after you started using a new cleaning product, air freshener, etc, try removing the new thing first, and monitor your dog for improvement.
2. Ensure your dog is on a balanced and appropriate diet, and keep it consistent. Frequently changing the diet your dog is on can cause confusion as you try to decide what ingredients they may be allergic to. If you notice a new reaction to a new food, go back to the previous diet and give your dog a couple of weeks to recover. If your dog has chronic issues like those outlined above, consider keeping a food and treat diary and sharing the information with your dog’s veterinarian so they can guide your decisions for future food purchases.
3. Regularly check and treat your dog for fleas; keep them on a veterinarian recommended flea prevention product because any lapse in treatment leaves them vulnerable. This includes dogs who are indoor only and even purse dogs who rarely touch the ground. Fleas can be anywhere and are easily carried into the home by accident.
4. Use pet-friendly, hypoallergenic grooming products. Hypoallergenic means fewer allergens. These products are made to have fewer ingredients or fewer irritants and may be gentler on sensitive skin.

If your dog has a sudden allergic reaction you may try the following:

• Give your dog a soothing bath. Use warm water (not hot or cold) and a dog-friendly shampoo that’s made for soothing the skin, such as an oatmeal based product. Do not use medicated shampoos unless directed by the veterinarian, and never use flea/tick shampoos.
• Apply a cool compress if the allergic reaction is isolated to a specific area. This may temporarily reduce itchiness and remove surface irritants.
• Administer Benadryl if your dog’s veterinarian recommends it (if your dog has any health conditions, don’t administer any medication with your veterinarian’s approval.)

Do allergy bumps ever go away on their own?

Allergy bumps can sometimes disappear on their own if the trigger is removed, but allergies do not generally go away. Recognizing the cause of an allergic reaction can be really helpful so you can make an effort to avoid the allergen in the future. The cause can be difficult to narrow down though, so if you’ve made a couple of attempts to manage a mild reaction with no luck, it’s important to get in touch with your dog’s veterinarian.

When to consult a veterinarian

If you see any of the following, its imperative to seek veterinary care quickly:

• Your dog experiences difficulty breathing or shows signs of a severe allergic reaction.
• The allergy bumps worsen or spread rapidly.
• Your dog becomes increasingly uncomfortable or distressed.
• Your dog’s behavior changes; listlessness or lethargy are concerning.
• Your dog’s mouth and tongue don’t look the right color (pale, bright red, grey, or blue mouth and tongue indicate an emergency and your dog needs veterinary care immediately.)
• Panting, or sudden vomiting or diarrhea.
• You are unsure about the cause or appropriate course of action.

If your dog is NOT exhibiting any of the above signs, and they seem pretty comfortable, you may be safe monitoring for a short while. Even if the signs are minor and resolve quickly it’s best to inform your dog’s veterinarian and ask if they can recommend a temporary at-home treatment solution in case it happens again.

Treatment options and likely costs

A minor allergic reaction might only end up costing an exam fee and some medication, the total visit might even be less than $100 in some areas. However if the allergy signs happen more than just one time, have lasted for a long time, or your dog’s allergic reaction is severe here are some costs you can expect:

1. Veterinary examination and diagnosis: $50-$200 depending on your region.
2. Allergy testing to identify allergy triggers: $200-$600 depending on what tests your dog’s veterinarian offers and recommends based on your dog’s signs.
3. Skin-friendly supplements or topical products: $20-$50 per month. This may include omega-3s, specialized wipes or sprays, or even shampoo and conditioner products.
4. Prescription medications or diets: $30-$100 per month depending on the size of your dog and the medications or diets prescribed. While this seems like a massive investment, if your veterinarian recommends a prescription medication or diet, it’s because they believe it will help your dog live a more normal, healthy life than they’d have without appropriate treatment.

Frequently asked questions

Are all allergy bumps in dogs itchy?

Allergy bumps in dogs can be itchy, but are not always. It’s important to consult with a veterinarian about bumps on your dog’s skin even if they’re not itchy.

Can allergy bumps be contagious?

Allergies and allergy bumps are not contagious to humans or to other animals. Allergies are an overreaction of the immune system to what would otherwise be considered a harmless substance. It is your dog’s own immune system reacting to something and this can’t be passed to other beings.

How long do allergy bumps typically ast?

The duration of allergy bumps varies depending on the cause of the reaction, the type of bump you’re seeing, as well as interventions used. Some may resolve on their own within minutes, especially if the allergen is removed. Bumps like pustules or papules may require medications AND allergy treatment in order to go away, and even then it could take 5 – 7 days days or 1 – 2 weeks.

Are certain dog breeds more prone to allergy bumps?

There are certain dog breeds well known in the veterinary and dog breeding community for being prone to allergies:

• Bulldogs (including English Bulldogs, French Bulldogs, and American Bulldogs)
• Retrievers (including Golden retrievers, Labrador Retrievers of all colors, and other Retriever varieties)
• Terriers (including West Highland White, Scottish terriers, and even Bull terriers)

Dogs with this breed heritage, even if cross-bred or mixed-breed, can be more prone to allergies than other breeds because of their genetics.

Can allergy bumps be a sign of a more serious health issue?

In some cases, allergy bumps can be a symptom of an underlying health issue, such as autoimmune disorders or hormonal imbalances. Allergies that are difficult to manage or unresponsive to allergy treatment could have one of those conditions as an underlying cause.