Scads of allergens exist in a dog’s internal and external environments alike, and any of them can induce an allergic reaction. In the outdoors, exposure to certain trees, grass, weed pollens or parasites may irritate the canine body into an allergic state. Inside the home, environmental and dietary allergens might include dust or dust mites, fabrics, rubber or plastic, foods and food additives.
Immunoglobulin E proteins are produced by the canine immune system through inhalation, ingestion or direct contact when the skin releases chemicals known as histamines. When a dog experiences an allergic reaction to some outside stimulant and his body begins releasing histamines into his skin, he will experience a tingling sensation throughout his body.
Once a dog feels the histamines tingling through his skin, the natural reaction is to scratch the itch. He will do so by chewing on his feet, scratching his body with his hind feet or rubbing his face on the carpet.
Visual skin symptoms often result in patchy hair loss, mutilated skin or crusted dry skin. In extreme cases, where dogs scratch until a lesions form, a bacterial infection may result. Ear symptoms may result if the ear glands overproduce wax in response to an allergen.
- Visage/Stockbyte/Getty Images