Hives on dogs: symptoms, diagnosis and treatment

Hives appear as bumpy, red, and itchy skin. You might notice them when your dog is excessively scratching. Lots of things can cause them, like allergies, insect bites, toxins or medication.

Early diagnosis and treatment for hives is essential. Like with hives on humans, they're very uncomfortable, but more importantly, they can signpost something serious, like a severe allergy. 

There's a risk that hives can worsen and lead to dangerous swelling, respiratory problems and anaphylaxis.

Below, we discuss what hives look like, what causes them and the dog hives treatment options.

Understanding hives

Before we discuss how to treat hives, we need to know what they look like, the symptoms and how they come about.

What are hives in dogs?

Hives simply mean itchy, bumpy skin. The condition is caused by a reaction to something, leading to a dog itching and causing skin damage. You'll usually see hives on a dog's face, legs and back, but they can appear pretty much anywhere.

The main issue with hives isn't necessarily the symptoms; it's what the symptoms are telling you. It's the body's way of saying, "Hey, something's up!"

For example, they can mean your dog has a bigger issue, like severe allergies, which will need prompt treatment.

Symptoms of hives on dogs

You'll see things like:

• Excessive itching

• Swelling

• Red skin

• A patchy, bumpy coat

The hives vary in size; they rarely get over 20 cm. You may see them in one localized area, or they may spread around the body. You’re likely to spot the localized, clustered hives more easily.

An itchy dog can mean many things, though. So never just assume it's hives. It can mean other irritants, like fleas or a skin infection, are causing the symptoms.

That’s why we always recommend speaking to your vet if you're concerned.

Causes of hives in dogs

As mentioned, hives are normally a reaction to something your dog has come into contact with or eaten.

Allergic reactions

Allergies are the number-one reason for hives. These can include allergies due to:

• Food

• Environment (pollen, dust mites, etc.)

• Insect bites and stings

• Contact irritants (chemicals, plants, etc.)

Allergy treatment usually starts with a process of elimination. It begins with finding the allergen and then using a combination of treatment and lifestyle changes to limit your dog's chances of encountering said allergen. While you and your vet investigate, they can prescribe things to manage the symptoms.

Medications and vaccinations

The side effects from common medications and vaccinations can sometimes result in hives. Always talk to your vet if this happens after your dog has been given any medication.

Do note, however, that vaccinations are safe, and your vet should chat through the common side effects of medication with you.

When in doubt, always read the documents that come with your pet's medication, especially the parts on side effects, and ask your vet if you have any questions or concerns.

Other triggers

Hives can occasionally mean something else is going on; it's not just a reaction to outside stimulants, and your pet's mental health or behavior can play a part.

Some dogs may get hives if they are extremely anxious.

Diagnosing hives

It's easy to diagnose hives. As mentioned, the symptoms are very distinct.

But finding the cause ofhives can be difficult. A vet won't just look at and treat the hives when you bring your dog into the clinic; they'll look at your pet holistically to try and determine what could be causing this problem.

Sometimes, it's part of a dog's ongoing allergic skin disease and may be an acute reaction to something, but other times, it can mean something else. It may also be a one-off reaction, like an insect bite or sting, or a long-term reaction.

Your vet will start with a physical examination, ruling out severe reactions like anaphylactic shock. They'll then ask for some background on your dog, like diet and medication, and if they have come into contact with anything different around the time the hives appeared.

Following that, they may perform an allergy test and blood tests to pinpoint what exactly is causing the hives or begin treatment.

Dog hives treatment and management

If your vet suspects a food allergy, they may perform an allergy test and prescribe an elimination diet.

Elimination diets can get tricky, so you’ll need to make sure you follow your vet’s advice on which prescription diets are safe and suitable for your pet.

You’ll need to be strict at home to make sure your dog doesn’t eat anything else while on trial. If successful, your dog might need a special diet for the rest of their life. 

Environmental allergens are tricky to pinpoint and can take longer to find.

Treatment, generally speaking, is about preventing hives, not directly medicating the symptoms. Allergy testing is useful for environmental allergens and sometimes no cause is found. You’ll need to treat the hives themselves while you try to find the cause. 

In cases where the owner can't remove the trigger, the vet may prescribe:

• Cold compresses to reduce itching and heat

• Antihistamines

• Corticosteroids (a type of anti-inflammatory)

• EpiPen in rare cases if reactions are severe

For at-home hives recipes, we recommend:

• Oatmeal baths

• Aloe vera

Always speak to your vet before using any home remedies on your pet, as some can cause more harm. 

When to seek veterinary care

There are two clear-cut cases where you need to seek urgent veterinary care. While hives are generally minor, you should escalate to a professional if:

• They're persistent or severe

• Your dog shows signs of anaphylaxis

Anaphylaxis, or an anaphylactic reaction, is very serious and life-threatening. The symptoms are:

• Convulsions and shaking

• Diarrhea and vomiting

• Difficult breathing

• Severe, sudden rashes

• Swelling, especially facial swelling

• Unsteady walking

• Collapse

Go to your vet immediately if your dog is having an anaphylactic reaction.

Preventive measures

Identifying and avoiding triggers

Your vet can help you find the trigger for hives. But, as mentioned, they can't always find what might cause them, especially if it's chemical or environmental. Managing and treating hives and allergies can be a long-term project.

You can help identify and avoid triggers with a few long-term steps, like:

• Keeping a journal of potential allergens: note everything your dog eats and check to see if hives appear after certain activities, like walking in long grass or when the house is dusty.

• Regularly cleaning your dog's environment—a clean environment—is a good proactive step to reduce the number of potential allergens.

• The right diet: continue to feed your dog a consistent, suitable diet and note any symptoms if you feed anything different. Our article on pet nutrition can help.

Strengthening the immune system

A balanced, commercially prepared diet, regular exercise and stress management can all increase your dog's general health.

While they won’t affect the severity of a dog’s symptoms, such as hives, they are an important part of maintaining your pet's long-term health. 

Remember, though, that it's never a replacement for proper medication, treatment, and veterinary advice. 

Regular veterinary check-ups

Finding the signs of hives early is essential. Sometimes, your vet can see these in their very early stages as part of routine health checks.

That's why preventative pet care should be top of the list.

How dog insurance helps hives

Overall, hives in dogs aren't usually a serious condition in isolation. But it can mean a deeper, more serious problem is present.

Always chat with your vet, as it's the most important step to rule out and treat underlying causes.

Of course, dog insurance can help treat conditions like this and can help you and your four-legged friend prepare.

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You're in it for the long haul, and your dog insurance should be, too. Get a quote for your pup today. *According to Forbes Advisor’s “Best Pet Insurance of 2023”

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