Hives on Dogs: How to Recognize and Treat Them

Some dogs just gotta scratch. But if your favorite canine is scratching more frequently or vigorously than normal, it’s time for a closer look. If hives are the reason your dog is so itchy, learning what to do about hives on dogs is the best way to provide your pup with relief.

While usually not serious, dog hives can appear without warning, which can be alarming for pet parents and intensely itchy for pets.  Let’s explore what causes these sudden, swollen bumps, how to identify them, and what you can do to help ease the itch.

What Are Dog Hives?

Dog hives (also called canine urticaria) are raised, itchy welts that can appear on dogs’ skin, usually in response to allergens. These swollen bumps can pop up anywhere on your dog’s body, from their face to their belly. Hives are essentially localized swelling within the dermis, the layer of skin beneath the surface. 

Luckily, hives are relatively uncommon in dogs. Recent studies found hives present in only 12 to 15 out of 10,000 dogs receiving care at veterinary hospitals (1, 2). 

While dogs of any age, stage. or breed type can develop hives, some breeds seem to be more prone to this itchy condition than others. In a recent study, urticaria was more prevalent in boxers, beagles, Rhodesian ridgebacks, French Bulldogs, and Vizslas than other breeds in the sample (1). In general, short-coated dogs – including pitbulls, English Bulldogs, and Dobermans – seem to face an increased risk of developing hives. 

Because exposure to allergens can cause hives, dogs in some regions are more likely to develop hives than others.  Dogs in warm, humid areas with more environmental allergens (like pollen-heavy regions) and insects might experience hives more frequently. But dogs in any part of the world can get hives.

What Causes Hives in Dogs?

Dogs can break out in hives for a variety of reasons. Understanding these potential triggers can help you identify and avoid them in the future. Here are some common causes:

• Insect bites or stings: Bees, wasps, ants, and other biting or stinging insects are a frequent cause of hives in dogs.
• Food allergies: Certain proteins in a dog’s diet can trigger an allergic response in dogs prone to allergies.
• Environmental allergens: Tree or grass pollens, dust or mold can cause hives in sensitive dogs.
• Plants: Direct contact with certain plants such as stinging nettles may cause hives.
• Medications: Some dogs may have an allergic reaction to certain drugs or vaccines.
• Harsh Environments: Extreme temperatures — both cold and hot — can cause hives in some dogs (3).

A recent study of 24 cases of canine urticaria found that insect bites or stings were the most common identifiable cause, followed by food allergies and drug reactions (1). 

What Do Hives Look Like on Dogs?

Recognizing hives on your dog is the first step in getting your pet the help they need. Here’s what to look for:

• Appearance: Hives typically appear as raised, round, or oval bumps on the skin. However, the size and shape of the bumps may vary. Some range from pea-sized to coin-sized, while others may join together to form large, irregularly shaped swollen areas or welts.
• Location: Hives can occur anywhere on the skin. But they are most common (and easier to spot) on sparsely-haired areas of the skin, including the underside of the belly, chest, and neck (4). Hives do not occur in the mucous membranes such as the mouth. 
• Characteristics: The bumps are often red or pink and may be warm to the touch. They can appear and disappear quickly, sometimes within hours.
• Duration: Most cases of hives will resolve on their own within 48 hours (1). Although rare, some dogs can have chronic urticaria, which may last six weeks or more.

Even with these guidelines, it’s easy to confuse dog hives with other common skin abnormalities. For example, hives can look a lot like a skin rash caused by a bacterial infection, called superficial pyoderma.

On areas of your dog’s skin covered in fur, both the rash and dog hives would appear virtually identical. That’s why it is best to seek veterinary care if you suspect hives, a skin rash, or other skin issues in your dog.

However, on sparsely-haired areas of your dog’s body, like the belly, it’s easier to tell the difference.  Dog hives typically look raised, red, and either uniformly round or merged into an irregular shape. A skin infection rash often features tiny pimple-like bumps (pustules) or flat red crusty circular regions (epidermal collarettes).

Duration can also provide a clue. Unlike many other skin conditions, hives can come and go quickly and often affect large areas of the body at once. 

Are Dog Hives Life-Threatening?

In most cases, dog hives are not life-threatening. However, hives can be a feature of or may occur prior to anaphylaxis, a potentially life-threatening allergic reaction.

If hives are accompanied by any of the following symptoms, you should seek immediate veterinary care:

• Difficulty breathing or wheezing
• Swelling of the face, especially around the eyes or muzzle
• Excessive drooling or difficulty swallowing
• Vomiting or diarrhea
• Lethargy or collapse
• Pale gums

If you notice any of these signs, don’t wait. Contact your veterinarian or an emergency animal hospital right away. And be prepared to provide any information you can about what may have triggered the response, so the care team can respond swiftly. 

Dog Hives Treatment Options

When treating dog hives, your vet’s recommendations may vary depending on what’s causing the hives and how severe they are.

Veterinarians typically diagnose the condition by collecting a detailed history and performing a physical examination. If your dog has long hair your vet may shave an area of their fur to assess the hives.

If the hives are recurring or the condition does not resolve, your vet may recommend testing to determine the cause. This could include fecal testing for intestinal parasites, an elimination diet to pinpoint specific food allergens, or conducting allergy testing on your dog’s skin and/or blood. 

Treatment options for dog hives vary depending on the severity of the condition. Antihistamines are often the first line of defense, helping to reduce itching and swelling. For more severe cases, your veterinarian might prescribe a short course of corticosteroids to reduce inflammation quickly. In rare instances of severe allergic reactions, an emergency epinephrine injection might be necessary.

If your veterinarian suspects your dog’s hives are due to food allergies, they may prescribe a special diet to solve the problem, such as a limited-ingredient formula or a novel protein diet.

Home remedies for dog hives

There are some at-home remedies you can try to help ease the itch for a dog breaking out in hives. However, always consult with your veterinarian before proceeding with an at-home or over-the-counter solution.

As a dog hives treatment, Benadryl (diphenhydramine) may help provide some itch relief. Though this over-the-counter antihistamine is made for humans, it is safe for dogs in certain doses. Before you give your dog Benadryl, always confirm the correct dosage with your vet, and ensure it contains no other active ingredients that could harm your pet. 

Cool baths with colloidal oatmeal can soothe itchy skin, and applying cold compresses can help reduce swelling and provide comfort. 

It’s important to note that in many cases, hives will clear up on their own within 24-48 hours. However, these treatments can speed up recovery and provide relief from uncomfortable symptoms, making your dog feel better sooner.

How to Prevent Dog Hives

While it’s not always possible to prevent hives, there are steps you can take to reduce the risk:

1. Identify and avoid triggers: If you know what caused the hives, do your best to limit your dog’s exposure to that allergen.
2. Regular grooming: Keeping your dog clean can help remove potential allergens from their coat.
3. Diet management: If food allergies are suspected, work with your vet to find a diet that works for your dog.
4. Environmental control: Use air purifiers and regular cleaning to reduce indoor allergens.
5. Temperature regulation: Keep your dog out of extremely hot or cold temperatures.

Remember, every dog is unique, and what works for one dog might not work for another. If your dog experiences recurrent hives, work closely with your veterinarian to develop a personalized prevention and treatment plan.

In conclusion, while hives on dogs can be alarming, they’re usually not a cause for major concern. By staying observant, acting quickly when needed, and working with your vet, you can help your best friend stay comfortable and itch-free.

References

1. Rostaher, Ana, et al. “Triggers, risk factors and clinico-pathological features of urticaria in dogs – a prospective observational study of 24 cases.” Veterinary dermatology vol. 28,1 (2017): 38-e9. doi:10.1111/vde.12342  
2. Fabrice T. J. Fosset, et al. “Retrospective Evaluation of Hypersensitivity Reactions and Anaphylaxis in Dogs (2003–2014): 86 Cases.” Journal of Veterinary Emergency and Critical Care, vol. 33, no. 5, 14 Aug. 2023, pp. 577–586, https://doi.org/10.1111/vec.13319
3. Bradley, Charles W, et al. “A Review of Cutaneous Hypersensitivity Reactions in Dogs: A Diagnostician’s Guide to Allergy.” Veterinary Pathology, vol. 60, no. 6, 29 July 2023, pp. 783–795, https://doi.org/10.1177/03009858231189298
4. Voie, K.L., et al. “Drug Hypersensitivity Reactions Targeting the Skin in Dogs and Cats.” Journal of Veterinary Internal Medicine, vol. 26, no. 4, 21 Apr. 2012, pp. 863–874, https://doi.org/10.1111/j.1939-1676.2012.00927.x