Anaphylaxis in dogs – signs and what to do

Updated 2026-09-30 · 1 sources

Based on: PDSA

See a vet now

This is an emergency – contact your vet or the nearest emergency vet right now. Anaphylaxis is a severe allergic reaction in dogs.

What to do now

What you can do now

Contact your vet.
Note when it started, how often it happens and what else you see.
Take a photo or short video to show the vet.
Let your dog rest somewhere calm.

Don't

Do not give any human medicine.
Do not wait if it gets worse.

What it is

Allergic reactions can be very serious and sometimes life threatening.^[1] Dogs can be allergic to almost anything, including insect venom, snake venom and certain medications.^[1]

Signs

Itchy skin
A rash
A swollen face, especially around the ears, eyes, mouth and paws
Breathing difficulties
A pounding heartbeat
Collapse
Vomiting
Diarrhoea
Drooling
Limping if a foot or leg is affected

Causes and risk factors

Insect venom
Snake venom
Certain medications

How vets treat it

Steroids
Fluids or a drip
Medication
Anti-inflammatories
Hospitalisation

What the experts say

“Your dog’s treatment will depend on how severe their symptoms are. If your dog is having a mild reaction, it’s likely that they will be given some medication (often steroids, and anti-histamines) before being sent home for monitoring.”
— PDSA [1]

If your pet is struggling to breathe, has collapsed, is having a seizure or can't stand up: go to the nearest vet now.

Not sure how serious it is?

OkPaw asks a few quick questions about your pet and tells you in 30 seconds whether it can wait. Free on Google Play for Android.

OkPaw is on Android now – an iPhone version is on its way.

Common questions

What can trigger anaphylaxis in dogs?

Dogs can be allergic to almost anything; common triggers include insect venom, snake venom and certain medications.^[1]

How serious is anaphylaxis?

Allergic reactions can be very serious and sometimes life threatening.^[1]

How might a vet treat a mild reaction?

Treatment depends on how severe the symptoms are. For a mild reaction, a vet may give medication, often steroids, before sending your dog home for monitoring.^[1]

Sources

PDSA

How this page was made: written with the help of AI from the sources below, then checked claim by claim against those sources. Urgency levels follow OkPaw’s fixed safety rules. It is guidance, not a diagnosis. How we write our pages

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