Recognising and Treating the Common Symptoms of Allergies in Dogs
07.10.2022 - Reading time: 6 minutes

Perhaps you are wondering why your dog has a dull coat or even hair loss despite being fed quality food? Or why he scratches himself all the time, even though there is no evidence of parasite infestation? Some dog owners even observe changes in the character of their pets that seem to occur suddenly and without reason. Not many dog owners associate these and similar symptoms with allergies in dogs. Yet more and more dogs suffer from allergies, which are a disease of the immune system.
- Recognising and understanding allergies in dogs in a timely manner
- Allergies in dogs – what are these?
- Diagnosing allergies and food intolerances in dogs
- What can the vet do to diagnose an allergy in you dog?
- Treatment options for an allergy in your dog: the avoidance strategy.
- The most common allergies in dogs at a glance
Find out here about diagnostic options and how to manage allergies in dogs.
Recognising and understanding allergies in dogs in a timely manner
Did you know that about one in five dogs suffers from allergies? And the trend is rising. There are several reasons for this alarming development and cross-allergies with manifold symptoms make a clear diagnosis difficult. In order to understand the dog’s allergy correctly, it is first of all important to uncover the possible sources of the allergy. These include environmental pollution, food intolerance, etc. Intolerance and allergy are medically completely different! This is also the reason for the enormous number of allergy sufferers in recent times. So: An allergy is a hypersensitivity reaction caused by the immune system.
Intolerances are hypersensitivity reactions that are not caused by the immune system. Certain components of the food cannot be digested e.g. due to a lack of enzymes, metabolic diseases or additives that can trigger hypersensitivity reactions. But it cause also be caused by breed-specific dispositions.
Allergies in dogs – what are these?
Just like human medicine, veterinary medicine understands “allergy” as an innate tendency of the body to respond to certain substances with a pathological reaction. These substances are not dangerous for the animal. The misdirected immune system classifies these substances as toxic or incompatible in the case of external (skin, respiratory tract) or oral (ingestion) contact and reacts with defence, thus putting the entire body on alert. Substances that trigger such an immune reaction are called allergens.
Dog skin diseases are often equated with allergies. Although dogs’ allergies belong to the field of skin diseases, this generalisation is not correct. Skin diseases in dogs require a more precise differentiation.
What are the most common allergies in dogs?
The most common allergies in dogs include environmental allergies, parasite allergies and food allergies.
When does an allergy occur in a dog?
It is impossible to predict when and whether an allergy will break out. As a rule, it takes several, or continuous, contacts of the dog with the allergens for an allergy to become manifest. This usually happens only in the second or third year of the dog’s life. Food intolerances, on the other hand, can occur in dogs at any age. Allergies and food intolerance can be managed well, if the cause is known.
Diagnosing allergies and food intolerances in dogs
An overview of the symptoms:
- Observe your dog closely over a few weeks. Is he constantly scratching certain parts of his body?
- Does he even have sore skin areas that he constantly licks?
- Does he regularly experience gastrointestinal problems, perhaps even diarrhoea and vomiting?
- Does he suffer from ear infection or other inflammation, skin oedema and swelling?
These can all be serious signs of one or more allergies. If you suspect an allergy in your dog, it is best to consult a vet or veterinary clinic that specialises in allergies. It takes a lot of experience and additional training to correctly diagnose allergies in dogs.
Tell the vet about any symptoms you have noticed in your pet over a long period of time. Keep in mind that flea saliva allergies and some contact allergies can occur seasonally or intermittently. Make videos, as the animals often do not show their natural behaviour in the treatment room.
The animal’s nature will change if it has a lot of psychological stress. If your “cuddly dog” does not let you touch him or scratch his head or ears, and perhaps even responds to your approach with aggressive outbursts, then this may well be due to a long-standing allergy.
What can the vet do to diagnose an allergy in you dog?
A vet has many options to diagnose allergies in dogs.
Different approaches
- Blood test
- Allergy test (intradermal test)
- Exclusion diet (favourite for food allergies and intolerances)
- Clinical exclusion procedure/exclusion diagnostics
Experience in veterinary diagnostics has shown that blood tests and intradermal tests (tests under the skin) alone do not provide reliable information on the dog’s allergy status.
In the end, the vet makes the diagnosis using the clinical exclusion procedure, gradually excluding diseases that are accompanied by the same symptoms. Blood tests and allergy tests can provide additional clues for the diagnosis.
An exclusion diet is prescribed, if there is suspected food intolerance. Initially, you will only feed meat that your dog has never eaten or has eaten only sporadically. This could be, for example, horse meat or ostrich meat with a side dish of carbohydrates. If the dog’s symptoms improve during this strict diet, then other ingredients are gradually added in order to determine what triggers symptoms. In any case, an expert should monitor this diet in order to recognise undesirable side effects or deficiency symptoms in time.
Treatment options for an allergy in your dog: the avoidance strategy.
Initially, the vet can give your four-legged friend medication to alleviate acute symptoms.
However, once the trigger of your dog’s allergy, i.e. the allergen, has been found, avoidance is the best medicine!
In the case of a contact, mite or flea saliva allergy, action is taken against the cause itself and fleas, mites or allergenic substances from the dog’s environment are removed or killed.
The food must be changed specifically and consistently if your dog’s allergy is due to an intolerance to individual ingredients in the dog food, such as certain sources of proteins, gluten or carbohydrate.

Suitable substitutions:
- Hypoallergenic dog food from a speciality shop that is free of contamination (PCR test).
- Hydrolysed diets: Amino acids in the food are broken down into molecular components, so that the immune system of the allergic dog does not recognise and attack them.
- BARF: Raw feed consisting mainly of raw meat and vegetables enriched with minerals and supplements according to the dog’s individual needs.
The advantage of BARF lies in the natural components, i.e. meat, vegetables, fruit, etc., which make up the main part of the diet. To avoid nutritional errors that could cause deficiency symptoms, seek advice and a feeding plan from specialist veterinarians for animal nutrition, trained animal healers or veterinarians initially.
At Maxi Zoo, you can find fresh meat and vegetable packages as well as ready-made dog meals.
Finally, factors you should consider:
- Your pet’s special diet must be followed for at least 8 to 10 weeks before its effect can be assessed.
- The food you choose must only contain ingredients to which your dog is not allergic.
- The feed should be free from preservatives and other by-products.
- Stay consistent – no exceptions are allowed! This is especially true for the choice of treats.
- A dog allergy cannot be cured, but with the right therapy, allergic dogs can live a long and symptom-free life!
The most common allergies in dogs at a glance
Environmental allergy
Parasite allergy
Contact allergy
Food allergies
A dog’s intolerance to food should be taken seriously, because a diseased intestine is unable to utilise vital nutrients such as vitamins, minerals and trace elements. Chronic intestinal inflammation leads to a weakened immune system and is a trigger for other autoimmune diseases and allergies in dogs.
Allergy in dogs – the symptoms
- Itching (head, back, ears)
- Frequent scratching and/or licking of some parts of the body
- Swelling, redness
- Hair loss on certain parts of the body (back of the back, base of the tail).
- Skin inflammation: on the head, ears, paws, armpits, groin region or back and abdomen.
- Ear infection (otitis)
- Gastrointestinal problems
- diarrhoea
- Vomiting shortly after eating
- So-called “hot spots”: hot, red and weeping skin inflammations
- Changes in temperament and behaviour (aggressiveness, fearfulness, nervousness)