Hives in Dogs
Written by Small Door's medical experts
Hives in dogs are usually a symptom of an allergic reaction. While most cases of hives are not life-threatening, hives can also be a sign of more dangerous allergic reactions or toxicities. Learning to recognize signs of allergic reactions, like hives, can help you get your dog the medical assistance she needs in a timely fashion.
In This Article
Hives, scientifically known as urticaria, are small, red, localized swellings on a dog’s skin. Typically, hives are caused by an allergic reaction and often develop and disappear suddenly. Hives can appear in large numbers which sometimes blend together and give the appearance of one large welt.
In dogs, hives most commonly occur on the face, legs, back, and flanks, but they can occur all over the body. This includes the tongue, throat, and eyelids.
The symptoms of hives in dogs are similar to the symptoms of hives in humans. You may notice:
Raised wheals
Itchiness
Swelling
Redness
A “bumpy” or patchy-looking coat
As in humans, canine hives are small, raised wheals approximately 1 to 20 cm in diameter. They can appear in a single location or be spread out over the body. Multiple hives in a clustered location may also give the appearance of a single larger swelling, which may be alarming for owners.
Hives can be itchy. If you notice your dog scratching, check her skin for signs of irritation, like hives, or other irritants, like fleas, and contact your veterinarian if the symptoms worsen.
Hives are a natural immune response. They are most commonly triggered by allergic reactions, which can have a wide variety of causes.
Common causes for hives in dogs:
Environmental allergens
Adverse drug reaction
Insect bite or sting
Exposure to chemicals
Plant irritants
Sunlight
Heat
Exercise
Stress
Genetic abnormalities
Your dog’s world is full of potential allergens and irritating substances. Food, pollen, dust, fleas, and many other allergens can all lead to hives. More acute allergic reactions, like reactions to insect bites and stings, can also cause hives.
Exposure to skin irritants, like chemicals, and plants like stinging nettles may cause hives as well, especially in short-haired dogs. If you notice hives on your dog after a walk through wooded or grassy areas, insects or plants could be a possible cause. Bear in mind that some causes of swelling, like snake or spider bites, could be potentially life-threatening if not treated immediately.
Medications can also cause allergic reactions in dogs. Contact your veterinarian if you notice hives on your dog after starting a new medication, and observe your dog closely for further signs of adverse effects.
Some incidents of hives in dogs are not caused by immune responses. Heat, exercise, stress, and genetic abnormalities may all precipitate or intensify hives in dogs.
Diagnosing hives in dogs is relatively straightforward. Diagnosing their underlying cause, however, is not.
Once your veterinarian has identified hives on your dog, he or she will give your dog a physical examination to check for other symptoms as well as any further signs of allergic reactions. As long as there is no risk of anaphylactic shock, your veterinarian will most likely then ask you for a history of your dog’s diet, changes in medications, and any relevant recent activities. Your veterinarian may recommend pursuing several different courses of action depending on these findings.
Allergy testing may be necessary in some cases, especially in cases of chronic urticaria. If food allergies are suspected, your veterinarian may also suggest an elimination diet to determine the cause.
Chemical irritants and plant irritants may be difficult to identify. However, most plant irritants resolve on their own without causing any lasting problems.
In many cases, however, your veterinarian may not be able to identify the underlying cause.
Hives in dogs often resolve on their own in a few hours. For severe or chronic cases, however, where the source of the irritant cannot be immediately removed, or the swelling is causing intense irritation to the dog, medications may be necessary. Your veterinarian may prescribe a corticosteroid or antihistamine to help control the hives.
Is there a cure for hives in dogs?
Hives that do not resolve on their own can be cured with medications like corticosteroids and antihistamines.
Are hives on dogs contagious for humans or other pets?
Hives are not contagious to humans or other pets. However, if your veterinarian suspects that the cause of the hives is a chemical or plant irritant like stinging nettles or poison ivy, keep other pets and family members away from potential problem areas.
What is the cost of treating hives in dogs?
The cost for treating hives will vary greatly depending on the underlying cause. Treatment will cost more if the allergen leads to a life-threatening allergic reaction that requires hospitalization. Most cases, however, are mild, and you can expect to pay for the office visit, diagnostics, and any medications your veterinarian recommends to treat the hives and the underlying condition.
In most cases, hives resolve on their own after a few hours. Understanding the cause of the hives can take longer. Some dogs simply have sensitive skin. Others may suffer from allergies that require long-term management. Learning how to manage your dog’s sensitivities will help reduce the risk of recurrence. For instance, dogs with grass allergies or sun sensitivities may need to wear protective clothing while outdoors.
Determining the cause of an allergy can take time, if it can be determined at all. However, by observing your dog you may be able to deduce some of the triggers for his condition.
Hives are not always preventable. If you know that your dog has a sensitivity or allergy to certain environments, substances, or medications, avoiding these will help. Other causes, like insect bites, are harder to avoid.
Talk to your veterinarian about the best way to prevent recurrent hives in your dog. He or she will advise you on the best protocols to take to avoid further reactions, and will also help you understand the risks of severe allergic reactions, like anaphylactic shock.
Is there a vaccine for hives in dogs?
There is no vaccine for hives. However, in some cases, vaccines can trigger an immune response that causes hives. These are usually mild, but always contact your veterinarian if your dog has a reaction to a treatment, medication, or vaccine.
Hives in dogs are small, itchy swellings, usually caused by an allergic reaction. Understanding the cause of your dog’s hives can help you prevent them, via medications or by making any necessary dietary or lifestyle changes.
