Yes, cats can be allergic to dogs and dogs can be allergic to cats although it is not something you hear much about probably because veterinarians are sometimes unsure which allergen causes an allergic reaction in a cat or dog. However, theoretically it is possible. The problem is that cat allergies appear to be a bit of a mystery even today. Allergens to which cats are allergic may be present in some dog breeds more than others. It appears that there is variability within the dog breeds in this regard. In contrast, a person is either allergic to all cats or none.
There appears to be different dog allergens such as dog saliva, Can f1, and dog albumin (Dr Elizabeth Falk) compared to the major cat allergen which is Fel d1.
Also theoretically, dogs which are more prone to shedding hair which would include both long and short-haired dogs may be more predisposed to creating an allergic reaction in a cat.
The American Kennel Club’s veterinarian Dr Robert Trimble said that he has heard of dogs being allergic to cats and vice versa. Dogs can be allergic to different allergens in food or the environment and therefore there is no reason to believe why they can’t be allergic to the feline allergen as well. It appears that dogs who are prone to being allergic to allergens may suffer from “an abnormal skin barrier that allows environmental allergens…to absorb through the outer-skin layer”. This allows allergens to be absorbed deeper into the skin layers resulting in an immune response part of which is the release of histamines causing itching.
An allergic reaction will create similar symptoms no matter what the allergen is. The cat or dog’s veterinarian will have to carry out tests to detect the allergen if possible. I’m told that allergy testing can be effective in identifying the cause of atopic dermatitis which is caused by allergens. Allergy testing is not recommended apparently for the diagnosis of food allergies which requires a food trial with a hypoallergenic diet.
Workers in the animal sector can become sensitised to animal allergens i.e. from both cats and dogs and other animals. It’s called “occupational sensitisation”. Control measures should be in place in the workplace combined with policies and education about the risks of exposure and becoming sensitised to animal allergens.
Clearly both dogs and cats have allergens on them and in them. These allergens affect people and the animals themselves. Allergies to dogs and cats affect between 10% and 20% of the population worldwide. In Korea, allergic rhinitis affects 37.6% of the population according to a study: Dog and Cat Allergies: Current State of Diagnostic Approaches and Challenges. There is a monetary consequence both in terms of the economy of a country and the treatment of people and pets suffering from allergies.
My research also indicates that cat allergies are twice as common as dog allergies. Does this means that dogs are twice as likely to suffer from an allergic reaction to a cat compared to the other way round?