Dogs and Hives: Everything You Need to Know

Dogs and Hives: Everything You Need to Know: When your dog breaks out in bumps that weren’t there before, it can be scary — especially if they’re itchy or swollen. These bumps are often hives (aka urticaria), a common skin reaction that signals the immune system is reacting to something. This guide helps you spot, treat, and prevent them — and understand when it’s serious.

What Are Hives?

Hives are raised, red or pink bumps (wheals) that appear on the skin, usually with swelling underneath. They can pop up quickly — anywhere on your dog — and often fade within hours to a day or two.

When hives affect deeper tissues (like facial swelling or throat swelling), that’s called angioedema, which can be more serious.

Common Causes & Triggers

Hives are the body’s “alarm” system — a reaction to something the immune system doesn’t like. Some common triggers are:

Insect bites or stings (mosquitoes, bees) — often the most frequent cause
Medications or vaccines — side effects or sensitivity to drugs or new injections
Topical products & chemicals — shampoos, cleaning products, lawn sprays, contact with plants
Food allergens — less common, but possible in sensitive dogs
Environmental allergens — pollen, moulds, dust mites may push sensitivities over the edge
Stress or temperature changes — sometimes a minor stressor or heat can trigger hives in a sensitive dog

Because hives can be triggered by many things, your vet may need to play detective to figure out the cause.

Signs & Symptoms to Watch

Look for:

Raised red welts or bumps anywhere on the body (face, neck, torso, legs, inside the mouth)
Itchiness, scratching, licking or biting at the bumps
Swelling, particularly around the face, lips, eyes, or throat (angioedema)
Excessive drooling if the mouth/swelling is affected
In severe reactions: breathing difficulty, vomiting, collapse — these are emergencies

If you spot facial swelling, trouble breathing or collapse, get to a vet immediately — this could turn life-threatening fast.

Diagnosing the Cause

Your vet will generally:

Do a physical exam — check the bumps, look for patterns
Take a history — when did the hives start, what changed (food, medication, new lawn treatments, etc.)
Rule out other skin issues — infections, mites, fungal conditions
Test / trial elimination — especially for food; may try stopping suspect meds or allergens, or dietary trial
Allergy testing / intradermal tests — sometimes done for persistent cases

Dogs that break out repeatedly might be good candidates for allergy investigation.

Treatment Options

Most hives respond quickly to treatment. Typical vet approaches include:

Antihistamines — e.g. prescribed ones safe for dogs
Steroids / corticosteroids — for stronger control in moderate to severe cases
Cold compresses / cooling packs — soothing relief to itchy bumps
Remove or avoid the allergen once identified
Severe cases — injection, IV fluids, hospitalisation and monitoring (especially with facial swelling or breathing problems)
For recurrent cases — immunotherapy (allergy shots), desensitisation, or long-term management plans

In everyday mild cases, warm (not hot) baths and vet-approved soothing shampoos may help ease the skin while the body recovers.

When Hives Become Serious

Hives on their own are often manageable. But watch out for:

Swelling in the throat or face
Laboured breathing, wheezing or change in respiratory rate
Collapse, weakness, vomiting or diarrhoea
Rapid recurrence or worsening over hours

If you see any of these, treat it as an emergency and get vet help right away.

Prevention & Management

Once the trigger is known (or suspected), you can reduce future flare-ups by:

Using pet-safe household cleaning products
Wearing protective clothing for your dog when walking through treated lawns or heavy pollens
Sticking to consistent, high-quality diets
Keeping flea/insect control up to date
Discussing with your vet preventive meds or desensitisation plans
Keeping a diary of exposures and reactions to spot patterns

How Pet Insurance helps

Many hives cases are mild and low-cost. But if you have:

Severe reactions needing injections, IV fluids or hospitalisation
Repeated allergy investigations or immunotherapy
Diagnostic tests (skin tests, elimination diets)

…pet insurance can help cover a portion of eligible vet bills. (Always check if the policy covers allergic / dermatological conditions).

You can see what PetsOnMe’s Dog Insurance covers and compare plans via Compare Cover.

Summary

Hives in dogs = sudden raised, itchy bumps (plus possible swelling) triggered by an allergen.
Many causes: insect bites, meds, food, topical contact agents, etc.
Most cases respond well to antihistamines or steroids, but emergencies must be handled fast.
Prevention depends on identifying and managing the trigger.
Insurance can cover the bigger episodes.