Why do dogs cause hives

Hives and Rashes (Urticaria) in Dogs

Hives or skin rashes (urticaria) are localized patches of red, swollen, usually itchy, skin. They often develop and disappear suddenly. Hives are relatively uncommon in dogs. The most frequent causes are insect bites or stings, shampoos, and medications. Other causes include contact with toxic plants or chemicals. Friction, sunlight, heat, exercise, stress, and genetic abnormalities may cause or intensify the rash. Hives may develop after inhaling or consuming allergens. Hives can be seen while a dog is in estrus ("in heat") or seen in puppies with intestinal parasites ("worms").

The wheals (eruptions) appear within a few minutes or hours of exposure to the causative agent. In severe cases, the skin eruptions are preceded by fever, poor appetite, or dullness. They can develop on any part of the body but occur mainly on the back, flanks, neck, eyelids, and legs. In advanced cases, they may be found on the mucous membranes of the mouth, nose, lining of the eyes, rectum, and vagina.

Often, hives disappear as rapidly as they arise, usually within a few hours. Treatment may not be required. They may return rapidly if exposure to the cause is not eliminated, however. Also, if your dog develops hives after receiving a vaccination or medication, contact your veterinarian immediately to see if treatment is needed. Treatment may include rapid-acting corticosteroids. If hives are chronic, environmental or food allergens should be considered as potential causes. Death does not commonly occur, unless anaphylaxis (a severe allergic event) or swelling of the respiratory tract is present.

Also see professional content regarding urticaria.

Dog Hives (Urticaria | welts): Causes, Diagnosis & Treatment

What Are Dog Hives (Urticaria)?

Hives, otherwise known as urticaria by medical professionals, are one abnormality you may see. They occur when your dog is allergic to something, such as an insect, medication, or food. Recognizing hives in dogs and understanding the cause is essential to relieving your dogs discomfort and preventing dog hives in the future.

What do dog hives look like?

• Dog hives look like raised bumps on the skin, usually about the size of a nickel.
• Hives are usually red in color; however, you may not notice redness if they are on a very furry part of your dog. In this case, your pets hives may only look like fur-covered bumps. Sometimes, its difficult to see the raised bumps, and you may only feel them when petting your dog.
• Dog hives can appear anywhere on the body, including the face, tongue, neck, legs, chest, abdomen, or back. They can affect just one area of the body or the entire body.
• Dog hives are very itchy. This may be the first thing you notice before seeing or feeling hives on your dogs skin. Your dog will likely be trying to scratch, lick, or bite the areas affected as it will be itchy.
• Hives usually happen very fast within minutes after exposure to whatever caused them.
• You may notice excessive drooling and a swollen/puffy face if the hives affect your dogs throat or mouth.

What causes hives on a dog?

Dog hives are almost always related to exposure to an allergen. Once exposed to an allergen, mast cells in your dogs body release a substance called histamine. Histamine causes blood vessels to dilate, which leads to raised welts on your dogs skin.

The most common allergens causing dog hives include:

• Insect bite or sting, or ingesting an insect (photo recommendation: dog playing with bee)
• Vaccinations
• Acute allergic reactions to medications (chemotherapy, vitamin K, antibiotics)
• Food allergies
• Environmental allergies (grasses, trees, mold, dust mites, etc.)
• Contact allergens such as shampoos, insecticides, cleaning products
• Ingesting or skin exposure to toxic plants

Much less common causes of hives in dogs include prolonged exposure to extreme temperatures (hot or cold), strenuous exercise, parasites, or significant psychological stress.

Insect bites/stings, food, and medications are the most common causes of hives in dogs.

How are dog hives diagnosed?

As a pet parent, it can be worrisome to see these skin rashes, but luckily, for your vet to diagnose your dogs hives. Your vet will use a combination of your history and their physical examination findings.

Its essential to think about anything new your dog may have been exposed to. Did you see them playing with a bee? Were they recently vaccinated? Did they start a new medication or a new food? During the physical exam, your veterinarian will look at your dogs skin to evaluate hives and where the hives are located.

If your veterinarian is having trouble diagnosing your dogs hives or the reason for their hives, they may perform additional diagnostics, such as blood work, skin cytology, skin scrapings, or fecal analysis.

How to treat & get rid of dog hives?

Treatment for hives in dogs can be simple or more extensive, depending on the cause, severity, and duration of the allergic reaction.

To get your dog quick relief from the swelling and itchiness related to hives, your veterinarian will usually administer an injection of diphenhydramine (an antihistamine) and a corticosteroid. Once your dog is feeling better and discharged from the hospital, your veterinarian may also recommend that you continue giving your dog Benadryl two to three times a day at home for a couple of days.

To prevent hives from reoccurring, you need to understand what caused them in the first place so that you can avoid the allergen in the future. If there is no apparent cause for your dogs hives (such as insect bite, medication, or vaccinations), it may be more challenging to understand how to prevent hives in the future. Environmental and dietary allergies are two possible causes of hives that may require further diagnostics and treatment.

Environmental allergies

If your dog has recurrent hives or has other signs of allergies, your veterinarian may recommend testing for environmental allergies with serum allergy testing or intradermal allergy testing. With these results, your veterinarian can create a plan to desensitize your dog to these allergies with allergen-specific immunotherapy.

If you determine that you cannot eliminate the allergens in your dogs environment or pursue allergen-specific immunotherapy treatment, your veterinarian may recommend:

• Giving your dog daily antihistamines (such as Benadryl, zyrtec, or hydroxyzine)
• Giving your dog other prescription-strength allergy medications such as apoquel or cytopoint
• Starting daily skin health supplements, such as omega-three fatty acids.
• Frequently bathing your dog with medicated high-quality shampoo

Food allergies

Allergies that stem from food can also cause recurrent episodes of hives in dogs. The most common cause of allergies in dogs include chicken, beef, dairy, and egg 2. Recurrent episodes of hives can also be related to dietary allergies. To diagnose a food allergy, your veterinarian may recommend a diet trial for 6-8 weeks with a prescription food or an over-the-counter diet with a different protein source, like fish or venison. If your dog responds positively to a food trial, you can continue the special diet long term.

Are dog hives dangerous?

Dog hives are rarely life-threatening. However, there are a few less common situations where hives can affect your dogs breathing and become dangerous.

• Hives in the face, neck, or throat can cause severe swelling that impacts breathing, which can become life-threatening.
• The presence of hives anywhere may indicate your dog is having or about to have an anaphylactic reaction, which causes constriction of airways and difficulty breathing. 3 Besides hives, other signs of anaphylaxis include vomiting, diarrhea, facial swelling, drooling, blue gum color, and collapse.

If you notice that your dog has hives, pay particular attention to how they are breathing and for any other concerning changes in their behavior. If you are concerned your dog may be having severe allergic reactions, take them to the emergency room immediately to rule out a medical emergency.

At-home remedies for dog hives

If possible, take your dog to the veterinarian if you notice they have hives, especially if this is a first-time problem. If your dog chronically or intermittently has hives and the issue has previously been discussed with a veterinarian, some at-home remedies may help relieve the allergic reaction.

• If the hives are not affecting your dogs face, neck, throat, or ability to swallow, you can administer Benadryl by mouth. Always discuss if this is appropriate for your dog with your veterinarian first and receive instructions about dosage and frequency.
• If the hives were caused by a contact allergen (such as grasses/trees or chemicals) or insect bites you can help relieve itchiness by bathing with a gentle oatmeal-based dog shampoo can help your dog feel more comfortable.
• Apply a cold compress to the hives or the most severely affected areas of your dogs skin. Be careful never to apply a cold compress for more than 10 minutes at one time, and always wrap the ice or cold object in a towel before applying it to your dogs skin.

Why Does My Dog Have Hives?

Seeing red spots on your dogs skin and watching him itch them furiously can be a bit alarming.

And finding out that your dog has hives from allergies or another cause can be even scarier.

While you can treat hives with a strong allergy medication most of the time, hives can also be the symptom of a life-threatening condition.

Heres what Dr. Ursula Oberkirchner, a veterinary dermatologist and owner of Advanced Veterinary Dermatology in Florida, had to say about hives on dogs, and what to do if you see these allergy bumps on your pup!

What are dog hives?

Hives on dogs, or urticaria, are most often caused by an allergic reaction, which means they develop after your dog is exposed to something hes allergic to.

Hives are a very characteristic symptom of an allergic-type reaction, Dr. Oberkirchner told The Dodo. Typically, hives develop within minutes or hours after exposure to the allergen.

Hives can be totally harmless and simply require an allergy medication to get rid of but sometimes they can mean something else is wrong.

Depending on the number, size and location of those hives, and if they are accompanied by other symptoms, such as trouble breathing or vomiting or diarrhea, hives can be a minor symptom or be part of a serious, even life-threatening, condition, Dr. Oberkirchner said.

An example of a life-threatening condition that causes hives includes anaphylaxis, which is when a dog has an extremely severe reaction to an allergen.

Certain cancers can also cause hives on your dog.

Your veterinarian will be able to help you determine whats causing allergy bumps on your dog. A thorough work-up by a veterinary dermatologist is often beneficial to help identify the cause of the hives and to manage them accordingly, Dr. Oberkirchner said.

What do hives look like on a dog?

Hives look like soft bumps that can range in size from small pebbles to egg-size and can be localized to one area of the body or develop all over the body, Dr. Oberkirchner said.

How to get rid of dog hives

How a vet will treat your dogs hives will depend on how severe they are.

The appropriate treatment is commensurate with the severity of the symptoms, and can range from giving your pet an antihistamine by mouth to requiring hospitalization with intravenous fluids and steroids, Dr. Oberkirchner said.

If you choose to give your dog antihistamines, make sure they dont include any added ingredients like decongestants or alcohol.

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You can also give your dog ordinary Benadryl, but contact your veterinarian first so they can tell you the appropriate dosage for your dog.

Its also recommended that antihistamines are taken alongside omega-3 fatty acid supplements to help your dogs itchy skin.

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You can also give your dog a bath with an anti-itch dog shampoo. To get the best results, look for shampoos that have both chlorhexidine and ceramides.

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Your vet might also prescribe other dog allergy treatments, including prescription medications like Apoquel, an injection (like Cytopoint) or steroids.

But truly the best form of treatment for dog hives is to figure out what your dog is allergic to and then keep him away from it, Dr. Oberkirchner said.

The key to long-term, successful management of hives lies within identifying what the pet is allergic to and, if possible, avoiding it in the future, Dr. Oberkirchner said.

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