This article is all about allergic reactions in dogs – from mild irritations, through to full blown anaphylaxis. Just as in humans, anaphylaxis is a serious medical emergency for your pet, and they will need veterinary help extremely fast. Therefore, knowing how to spot the signs and symptoms could help you get much needed medical support to your pet when time is critical.

Minor allergies can also make your pet unwell and unhappy, and there are things you can do to help.

What are allergies?

Allergic reactions occur when the body’s immune system reacts inappropriately to the presence of a substance it wrongly perceives as a threat. In order to develop an allergic response, the body usually has to be exposed to something to trigger the immune response (although it is possible to have an idiopathic response for which no cause has been identified!). The allergen is usually touched, inhaled, swallowed or injected (perhaps during a routine vaccination or by an insect sting).

What can cause allergic reactions?

Pets can have an allergic reaction to all sorts of things, from grass to food. In fact, it’s possible for a dog to be allergic to just about anything.

Common allergies include:

Medicine – such as vaccines, flea medicines and antibiotics

Bee stings, wasp stings and insect bites

Chemicals – cleaners and air fresheners

Plants – nettles and grass – yes, dogs can get Hayfever!

Flea allergy dermatitis FAD – sensitivity to flea saliva so even just one or two fleas can cause your pet to become itchy and uncomfortable for many weeks.

What causes an allergic reaction?

The body doesn’t react to the irritant directly. Instead, it reacts to histamine and other chemicals released by cells damaged through the immune response.

Severe, allergic reaction or anaphylaxis

Anaphylaxis is a serious allergic reaction that is rapid in onset and can prove fatal. Symptoms typically come on over minutes to hours. A dog showing symptoms of a severe allergic reaction needs lifesaving veterinary treatment and you need to respond rapidly.

How will I know if my pet is having an allergic reaction?

They may be biting or licking the affected area as it is itchy

The area may be swollen, red and have visible allergic hives (raised red patches)

They could be sneezing, congested and uncomfortable – as with hayfever

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A severe allergic reaction (anaphylaxis) may also cause

• Breathing difficulties
• A fast, pounding heartbeat
• Vomiting and/or diarrhoea
• Shock, collapse and unconsciousness
• Cardiac Arrest

When to get help fast

If you see the animal begin to develop breathing problems and swelling around their throat, get veterinary advice immediately.

Transport them to the vet in the pet recovery position with their lower back slightly higher than the rest of the body (pad underneath their body to keep their back straight).

To learn how to put your dog in the recovery position click here: https://firstaidforpets.net/pet-recovery-position/

If they lose consciousness and stop breathing you may wish to start CPR.

To read our article on how to perform CPR for dogs click here: https://firstaidforpets.net/cpr/

If the reaction is caused by a bee sting and the sting is still visible, it should be scraped out using a credit card or thumbnail, but not removed with tweezers, as this could squeeze more venom into the wound.

Treatment for mild allergic reaction

Antihistamine can help mild allergic reactions

If an animal is having a mild allergic reaction, your vet may prescribe an antihistamine tablet or syrup and this can be very effective. However, the medication will take at least 15 minutes to work. If you are concerned that the reaction could be systemic (all over) and life threatening, phone your vet immediately.

In addition, if they are having a minor skin allergy, washing the area in cool water may help. Your vet will be able to prescribe an oral antihistamine if necessary.

Treatment for severe allergic reaction

Adrenaline can help severe allergic reactions 

Your vet is likely to give adrenaline. This is because adrenaline (also known as epinephrine) acts quickly to constrict blood vessels, relax muscles in the lungs to improve breathing, stimulate the heartbeat and helps to reduce swelling.

If your dog has a more severe reaction, they could be admitted into the veterinary hospital for further treatment. This could include a drip to give fluids, medication directly into the vein. Additionally, if your dog is having trouble breathing, a tube may be placed into their windpipe to supply oxygen and ease their breathing difficulties.

Safety precautions for pet owners to take

The key advice is to avoid any known allergens if at all possible. However, your pet can develop a reaction to any foods and it can be very difficult to work out which one is the culprit.

Furthermore, do not smoke around your pet and be careful which chemical cleaning products you use around your house.

About us

First Aid for Pets provides this information for guidance. It is not in any way a substitute for veterinary advice. The author does not accept any liability or responsibility for any inaccuracies or for any mistreatment or misdiagnosis of any person or animal, however caused.