Tale of Tails



An allergy is defined as a “misguided reaction to foreign substances by the body’s immune system”. Normally the body gets used to an allergen, but sometimes the immune system is hypersensitive and over-reacts to a benign allergen. An excess production of histamines is part of this immune system response, which results in the symptoms we know as an allergy.


Dogs can develop allergies in the same way that humans can – and like in humans, some dogs are more sensitive than others. This sometimes seems to be related to breed, and sometimes related to the environment the dog lives in, but sometimes it is just individual differences (in the same way it is in humans).

Allergies vary in severity; for many they are a nuisance causing itching, scratching or digestive discomfort, but for some they are life-threatening with anaphylaxis.

Allergies and related issues are responsible for many vet visits and as those with dogs who suffer with allergies will know (like our very own Dory Adelie and Sparrow), it can take a long time and get very costly when you are investigating the specific cause of an allergy, and then in turn to trying to manage the symptoms of it.

Below we group together the types of allergens that dogs are most commonly sensitive to, listing common symptoms of that type of allergy and the usual ways of managing it. We then break it down into any specific allergens, explaining anything unique to that allergen.

Food Allergies & Sensitivities

True food allergies (where it is an immune response) are fairly rare – most of the time when people talk about food allergies, they are referring to food intolerance or sensitivities to specific ingredients. This is a reaction that gradually develops in response to a given ingredient in their food, often seemingly starting “out of nowhere”, however unfortunately once it is developed it rarely goes away. It is fairly common and rarely inherited. Food intolerances are usually best dealt with by eliminating the allergen from their diet – finding the specific allergen is another matter however!!

Common Symptoms:

  • Diarrhoea or vomiting
  • Flatulence & chronic gas
  • Coughing, sneezing, wheezing
  • Chronic external ear infections
  • Frequent scratching & hair loss
  • Red, inflamed skin
  • Itchy rear end
  • Chewing paws
  • Poor growth in young dogs

Specific Allergens:

  • Grain intolerance e.g. wheat, corn,
  • Protein intolerance e.g. chicken, beef, soy, chicken eggs,
  • Dairy allergy (due to the protein in dairy)
    • NB: All dogs are mildly lactose intolerant but some are more sensitive than others


The first aim is to identify the offending ingredient as often it can be really difficult to separate out the ingredients and work out which is eliciting the reaction. Generally the best way to do this is through an elimination diet trial – which usually involves giving your dog a special prescription diet, usually for 8-12 weeks, making sure it removes their symptoms (to identify that it was something in their food) and then gradually reintroducing ingredients and assessing their reaction. When symptoms return you can effectively identify the offending ingredient and subsequently adjust their diet, making sure to avoid the offending ingredient.

Unfortunately this takes a fairly long time as you need to give your dog long enough to adjust to each stage to get an accurate representation. Many dogs also have multiple food intolerances so you may find that even without the presumed offending ingredient, they still get symptoms – and then you will need to try again to identify the other offending components. Additionally you have to be incredibly strict throughout the process – not feeding anything other than the prescription diet, including no other dog treats, table scraps etc. and making sure they can’t get hold of other food from the bin, otherwise it invalidates the trial.

There is also the possibility that you will go through the initial process, only for their symptoms to continue. In some this is because their symptoms were not due to their food as many allergy symptoms overlap, or your dog might be unlucky enough to have multiple allergies.

Environmental Allergies

A common cause of allergic symptoms in dogs is their environment. Many dogs seem to be magnets to rolling or covering themselves in the worst offending allergens including grass, plant pollen and dust!

Common Symptoms:


Specific Allergens:

  • Pollen allergies
  • Dust allergies
  • Grass allergies
  • Mold allergies

Other Allergies

Insect Bite/Sting

Most dogs when they are bitten or stung by an insect will experience localised itching or redness (or similar mild symptoms) for a short period of time. However some dogs are hypersensitive to the saliva of the insect and therefore have a more severe reaction to any bites or stings, which can end up spreading.

  • Flea allergy dermatitis – most common
  • Also bee stings, spider bites etc.



**information sources**

Pet Health Network: Allergic Reactions
AKC: Dog Allergies
VCA Hospitals: Allergies in Dogs
Food Allergies in Dogs