Allergies in dogs
Updated: Apr 14
Itchy dog? At this time of year allergies are rife, and thanks to changes in climate and more advanced allergy testing, allergies in dogs are becoming more and more apparent. But how do you know if your furry friend has an allergy and how can you find out exactly what they are allergic to? We look at some of the allergy symptoms often seen in dogs - and what could be the cause.
How can you tell if a dog has allergies?
Allergies in dogs generally fall under three categories – flea allergies, environmental allergies and, less commonly, food allergies. 10 of the most common symptoms of allergies in dogs are:
1. Itchy or red skin
2. Hair loss or scaly skin
3. Excessive scratching or licking
5. Swelling around the face, ears or eyes
8. Unpleasant odours from skin, coat or ears 9. Sore, runny eyes
10. Changes in appetite.
Flea allergies in dogs
Fleas can be a problem all year round, but tend to cause more issues in the summer, as the warmer weather helps to speed up the flea lifecycle. If you suspect your dog has fleas it’s important to establish whether they may just have picked up a “hitchhiker” from elsewhere, or whether you have a flea infestation at home.
Flea allergy dermatitis (FAD) is the most common skin complaint in our domestic pets and can begin at any age although it usually appears between age two and five. It is believed that the saliva from flea bites is actually the cause of the irritation and even just one or two bites can cause quite severe itching. You may also notice hair loss or scabs on the skin.
Dogs with other allergies like environmental allergies also tend to be more likely to develop flea allergy dermatitis.
Treating flea allergy dermatitis
Fleas can be detected with a dog flea comb through the hair but if you are unsure whether your dog has fleas, the best approach is to treat for fleas anyway. Skin tests or blood tests can also be used to detect whether your dog has FAD.
The most important part of treatment is preventing flea bites in the first place, so rigorous flea control is vital. If short term relief from severe discomfort is needed your vet may recommend a steroid treatment. Omega 3 fatty acids for dogs can also help to support the natural anti-inflammatory actions of the body.
Environmental allergies in dogs
Dust, dust mites, mould, pollen and grass are amongst the most common environmental allergies, so rolling around in the grass is going to leave your dog with more you bargained for. Often the more your dog is exposed to allergens, the more severe the allergic response becomes so without diagnosis and treatment it will become worse.
Signs that your dog is suffering from an environmental allergy may include lesions on the underside or top of the feet, itchy skin, sore runny eyes, sneezing, and inflammation or areas of hair loss. Occasionally you may also see respiratory symptoms in your dog as a result of seasonal allergies like hayfever.
Diagnosing and treating environmental allergies in dogs
The most common way of identifying this type of allergy in dogs is testing (where a small amount of an allergen is injected under the skin). Lifestyle changes like walking in different areas to avoid grass may also help you to identify allergens by a process of elimination.
Your vet may suggest steroids if your dog has really itchy and uncomfortable skin as it can provide welcome relief from the allergy symptoms – but be aware that there are side effects which can impact your dog’s health in other ways such as high blood pressure and kidney disease.
Antibiotics may be recommended if your vet feels there is a secondary infection as a result of your dog’s itching, licking and chewing.
Symptomatic relief for environmental allergies can be given in the form of antihistamines for dogs (for example Benadryl) to reduce itching – but you should always check with your vet before giving over the counter medication.
Again, supplementary nutraceuticals like Omega3 essential fatty acids can also help to maintain the natural anti-inflammatory actions of the dog’s body and reinforce the skin’s barrier.
Dog allergies to food
Food allergies in dogs are less common than other allergies, but can be just as unpleasant for your dog if they are suffering. Whilst food allergies in dogs are a genetic issue, it is believed they may be triggered by feeding your pet the same food over a long period of time, thereby overexposing them to one particular allergen. Commercial pet foods can also include ingredients that are biologically inappropriate, like grains or preservatives which can in turn create stress on the digestive system.
Amongst the most common allergens are beef, chicken, dairy, wheat, legumes and egg, and most dogs are allergic to at least two foods if not more.
How do I know if my dog has a food allergy?
Common symptoms of food allergies in dogs are vomiting, diarrhoea, decreased appetite, itchy skin, hives, infections in the ears or paws, inflamed areas of skin and patches of hair loss from excessive scratching and licking.
Treating food allergies in dogs
Symptomatic relief for digestive upsets can help your dog feel more comfortable in the short term, but the main approach to a food allergy is to identify the foods causing the problem using what is known as an elimination diet. For dogs this means introducing a “novel” protein (one that your dog hasn’t eaten before like rabbit, for example) and carbohydrate into the diet. Usually your dog will be fed on this single novel protein for at least 8 weeks, after which other foods can gradually be reintroduced while the results are closely monitored.
If your dog has shown a good improvement on the new diet there is no rush to add back in foods which could be problematic. However, it is a good idea to have several protein sources and rotate your dog’s food as limiting the diet to one protein could mean that over time they develop an allergic reaction to the novel protein as well.
Research has also shown that boosting the population of beneficial bacteria in the digestive system with prebiotics can help to keep food allergies and digestive upsets at bay.
Always seek advice from your vet
If you suspect that your dog is having an allergic reaction you should contact your vet as soon as possible to identify the cause and establish a course of treatment as soon as possible. In severe cases an anaphylactic response may be seen in which case your dog will need urgent medical attention.
This article is in no way intended to constitute medical advice and proper diagnosis from your vet is always recommended.