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Tell-tale Signs that Your Dog Has Allergies…

Written by Anna Hollisey


Spaniel having a scratch in the grass

The top five signs that your dog has an allergy – and how to work out which allergen is causing it. 

Hey Pooch, What’s Up?

Did you know that dogs can suffer from allergies just like humans? And some of their common allergens are the same as ours. 

But first – what are the signs that your dog could have an allergy? We list the most common symptoms below.

Important Note: Before we get into those allergy symptoms, please be aware that this article isn’t enough to make a medical diagnosis. You should always check any worrying symptoms with your veterinarian.

Top 5 Allergy Symptoms in Dogs

1 Itchy Skin. 

If your dog’s scratching and biting their skin, they could have an underlying problem/learn/dog-health/your-simple-guide-to-allergies-in-dogs. It’s tricky to identify, because itchy skin can be caused by different types of allergy: for instance, a food intolerance can cause itchy skin, but environmental allergens (like pollen or dust) or fleas can cause this symptom as well. 

If your dog has been suffering from itchy skin for a long time, your vet may suggest examining their diet or eliminating common problem foods (beef, chicken, eggs, dairy, and wheat). 

2 Swollen or Puffy Eyes, Ears, or Face. 

Have you ever wondered why humans and dogs have puffy eyes or lips when they get an allergic reaction? It’s because our immune systems use histamines to defend the body – triggering watery eyes, sneezing and scratching in order to get rid of allergens. When our bodies issue high levels of histamines, these symptoms cause visible redness and inflammation. 

So, swelling around the eyes or ears can indicate the presence of an allergen such as pollen or parasites. It can also be linked to a histamine-triggering food like yoghurt or processed meat

3 Nasal drip, Watery Eyes, and Sneezing. 

Drips, dribbles, runny eyes and noses are all caused by histamines. The drippiness is the body’s way of flushing out allergens. 

This symptom is most likely to be caused by environmental or parasitic allergies like pollen, dust, mould, or fleas. Is it hay-fever season? Can you find fleas on your dog’s fur?

4 Vomiting and Diarrhoea. 

Gastrointestinal symptoms can be caused by a wide range of pooch problems. For instance, your dog might have chewed on a toxic plant… or ingested some unsuitable human food. Even swallowing a large amount of sea-water can cause stomach upset. Unfortunately, dogs love doing most of these things!

As dog owners, we’re all accustomed to occasional vomit puddles, and know that our dogs will usually be fine by dinner-time. But regular bouts of vomiting and diarrhoea could indicate a food intolerance. If you suspect that’s the case, you can try adjusting their diet with care. ‘Hypoallergenic’ dog food is readily available, and made without the key problem foods (chicken, beef, eggs, dairy and wheat). 

5 Anaphylactic Shock. 

Like humans, some dogs suffer from anaphylactic shock when exposed to key allergens like bee stings. The first signs you’ll see are dribbling and difficulty breathing as the lungs contract. There may be a raised heart rate, too. If your dog develops any sudden symptoms like these, seek urgent veterinary help. Anaphylactic shock can be treated by intravenous injection.

Identifying Common Allergens

When you take your dog to the vet, they’ll probably ask you some questions to figure out which allergens your dog’s encountered.

Try monitoring their symptoms to see if there’s a pattern – linked to seasons or places – and track what your dog eats if you want to check for food allergies. Carry out some more basic checks before you head off to the vet:

  • Check for fleas (flea allergy dermatitis)
  • Check the pollen index for your area
  • Look for mould inside the home
  • Check with family members whether your dog has eaten something unusual.

Further Reading

Is wheat always bad for dogs? Read about the common misconceptions surrounding wheat and gluten/learn/dog-food/is-wheat-bad-for-dogs. If you’re investigating your dog’s diet, read this article about spotting the signs of food intolerance./learn/dog-food/5-signs-that-something-is-wrong-with-your-dogs-diet From antihistamines to natural remedies, we’ve rounded up options for treating allergies in dogs here./learn/dog-health/what-can-i-give-my-dog-for-allergies