Dr. Franck, I’m afraid my dog has allergies! I’ve seen him scratching himself all day! What can I do about it?
First, let’s talk about what these allergies are, and then we’ll quickly get to the potential solutions.
Let’s start at the beginning: allergies in dogs are caused by abnormal reactions of an animal’s immune system.
These reactions may be triggered by certain elements in the dog’s diet or environment
- plants
- trees
- pollens
- hair
- household products
- insects
- fleas
- etc.
Symptoms can be pretty vague, often (but not exclusively) manifesting themselves as
- reddening of the skin
- itching
- patches
- skin inflammation
- hair loss
- discharge (often clear) from the nostrils
- digestive signs such as bloating
- vomiting
- diarrhea
In short, these are the most common signs, and there may be many others.
So, Dr. Franck, what can I do to confirm that my dog does indeed have allergies?
Generally speaking, the diagnosis will be made by a veterinarian.
You can rarely do it yourself at home. The vet will examine the dog’s history and symptoms. Then, if he suspects a food allergy, he’ll recommend an eviction diet, i.e. a special diet (avoiding certain ingredients) for a few weeks.
Towards the end of the 10-12 weeks, we generally reintroduce what we’ve been avoiding all this time, and we can get a good idea if the signs come back quickly.
Then, if you suspect an allergy related to something in the environment, there are intradermal tests performed by veterinary dermatologists. These will tell you what your dog is reacting to (or not). It may also be necessary to subject the animal to blood or other skin tests.
In short, it would take a long time to explain everything, and remember that there’s no single way to proceed.
Then what happens with the treatments afterward?
Once the responsible allergens have been determined, your vet can then devise a treatment or preventive measures best suited to your dog’s needs.
As explained above, sometimes a change of food will be required, although this isn’t always necessary either. Sometimes, there are changes to be made in the environment, as certain allergens can be avoided.
Medications such as steroids, antihistamines, and other anti-allergy molecules are also available to treat allergies and should be prescribed by your vet. It’s important to follow the treatment instructions and carefully monitor your pet’s reaction to the treatment.
Desensitization treatments are also available in certain situations. Such treatments are also available for humans. This will not completely resolve the allergy, but will greatly reduce the signs observed. In addition, topical products such as soothing lotions and medicated baths can also be used to soothe your dog’s skin and relieve allergy-related symptoms.
Finally, a flea preventive treatment is recommended for all outdoor dogs. The reason for this treatment is that fleas have been and still are one of the most frequent and easily preventable causes of skin problems in dogs.
In summary, you now understand that there’s a lot to know about allergies in dogs.
This article was only an overview, but you already know more than you did a few minutes ago! It takes patience and effort to deal with this kind of problem.
Fortunately, there are many treatment options available, and in the end, your dog will be more comfortable with them.
Tell me, I’m curious: has your dog ever had a sign?
Further Readings
- I Have A Fat Dog: What Can I Do?
- Temperature in Dogs: What You Need To Know
- Vaccines For Dogs: Reactions, Symptoms (and more)
- The Complete Guide To Dog Coughing (What To Do, Symptoms)
- How Often Should I Take My Dog To The Vet?
- How Often Should I Go Out With My Dog?
- How Long Are Dogs Pregnant?
- Urinary Problems in Dogs: What You Should Know
- The Complete Dog Diarrhea Guide

Francis Lagacé has been a member of the Ordre des médecins vétérinaires du Québec since 2004. He practiced for 16 years in several veterinary clinics across Canada. He treated animals of all types, mainly cats, dogs and exotic animals (rabbits, rodents, ferrets, birds, reptiles). Since 2020 he has been working in the field of veterinary pharmacovigilance. You can find him on LinkedIn.