Dog - Contact Allergies

What are allergies and how do they affect dogs?

Allergic reactions are very common in dogs and are fully described in a separate handout on Allergies and Hypersensitivities.

Is there more than one type of allergy?

Yes, there are at least five common types of allergy in the dog:

1. Flea
2. Food
3. Contact
4. Inhalant
5. Bacterial hypersensitivity

I have been told that my dog has a contact allergy. What is this?

Many substances can induce contact allergy. These include certain plant materials, e.g. pine oil (or even pine needles), disinfectants, wool, nylon and dyes. Sometimes shampoos, ointments and insecticides used in the treatment of skin disease can be implicated.

Because dogs are covered with hair, contact allergy is a rare disorder compared with people where it is relatively common.

My dog keeps licking himself underneath, particularly around his private parts which are inflamed and sore. Is this likely to be due to his contact allergy?

Symptoms often usually involve intense pruritus (itching) on contact sites such as the feet, skin, scrotum, elbows and hocks.

Does the condition develop rapidly?

This depends on the cause allergen. Usually contact hypersensitivity develops relatively slowly. Please see below, irritant dermatitis.

Is there any difference between contact allergic dermatitis and contact irritant dermatitis?

Yes. Contact irritant dermatitis is not uncommon in dogs and should be distinguished from a contact allergy. Only a small percentage of dogs will have an allergic response to a contact allergen whereas all dogs will have a skin reaction on exposure to an irritant.

Common irritants include creosote, concentrated disinfectant or detergent solutions.

Clinical signs of contact irritation are similar to contact allergy but occur very rapidly.