Allergies in Dogs, a vet's guide

What are the top ten allergies for dogs, in order?

Most people are surprised to learn that chicken, beef and dairy are the most common allergens for dogs. Some of the signs may easily be misdiagnosed by owners and can include excess paw licking, waxy ears and intermittent runny stools. Contrary to popular belief, true grain allergies in dogs are relatively uncommon and so a grain free beef diet is probably not the ideal go to for a dog with food allergies or sensitivities, even if it’s labelled as ‘hypoallergenic’.

What is the prevalence of allergies in dogs? 

It’s not clear what the exact prevalence of food related sensitivity and allergies is in dogs because diagnostic tests are rarely carried out and instead, suspect cases are usually treated with trial and error ingredient exclusion diet trials instead. There is evidence however that dog owners looking for hypoallergenic dog food has risen by up to 75% in recent years and that some of the common signs associated with such conditions like gut and skin disease are soaring. 

What are the other dietary options available for those allergic to e.g. chicken?

As it’s mainly the proteins found in standard commercial dog foods that tend to trigger cutaneous and gastrointestinal reactions in dogs, vets usually recommend affected dogs either use novel protein diets that the dog has had limited exposure to in the past or a diet in which the protein is ‘treated’ by hydrolysis so the immune system does not get triggered by it. For the former category, vegan diets which tend to use yeast and pea proteins have become more widely used, and to a lesser extent insect protein diets. Soaring insect protein prices have made the latter unaffordable for many, and it’s actually plant-based diets that are expected to become more mainstream in the future as more and more research is published to demonstrate both their safety and efficacy. Hydrolysed meat protein diets are still recommended by some, but a move away from ultra processed meat and more palatable alternatives for dogs in general is likely to render this option less sought after over time. 

How serious an allergy is pollen for dogs? Do they suffer from hay fever at this time of year like humans do?

Seasonal allergies brought about by things like pollen are definitely thought to contribute to a dog’s presentation with clinical signs of allergic disease, though prevalence is likely lower than in humans. In general the more allergic triggers that accumulate in a dog at one time, the more likely it is that the dog will exhibit debilitating signs like itchy skin. 

How do you really test for dog allergies? Do you need to see a vet? Prick tests etc as in for humans? 

It is possible to do allergy testing at the vet. One of the most reliable forms is via skin prick tests in which several common allergens are inserted under the dogs skin and the level of ‘reaction’ is recorded and analysed. There are also blood tests that can look for certain antibodies. The issue is that a dog may test positive for many allergens that could not be the cause of the observed clinical signs and sometimes it’s not possible to completely exclude them from the dogs living environment anyway  e.g dust mites. These tests can also be costly and time consuming so it’s common for them to be performed as a last resort if medical / dietary management is not being tolerated or working. There is some success reported managing these extreme cases with allergy targeted immunisation therapy. 

What are the symptoms of dog allergies?

The most common symptoms are itchy skin and ears, which includes paw licking. Over time this can lead to redness, saliva staining, swelling and hair loss. Some dogs present with gastrointestinal signs, like vomiting or diarrhoea. 

Might there be lots of undiagnosed dog allergies around?

For sure - as mentioned above, if a dog has the signs described above, it’s common to start a hypoallergenic diet trial, and cover for skin parasites treatment before elaborate tests are conducted to try and work out what the dog may be allergic or sensitive to. 

Any trends you as a vet have seen or heard of?

A lot of people seem to turn to raw diets when they find out their dog may have dietary allergies - it’s common for them to read misinformation online that their dog is reacting to the starch and grain in their commercial kibble - though this is possible, the evidence shows that these are less likely to be the cause of the dogs signs and that feeding raw actually puts the dog at more risk due to foodborne pathogens in uncooked meat. As a vet, I would generally advise a vet approved, nutritionally complete commercial vegan diet as first point of call, preferably soy free and perhaps a hydrolysed diet if the former was not working out. 

Dr Guy Sandelowsky's range of pet food and supplements are available at: https://omni.pet/