Allergies can present a variety of symptoms, but in the dog, the most common symptoms occur as skin irritations: itching, scratching, digging, and gnawing at the skin, often to the point of creating open raw wounds over large areas of the body. Chronic ear infections are another common symptom. Occasionally dogs will have respiratory symptoms such as coughing, sneezing, or a nasal or ocular discharge. Food allergies may produce, in addition to skin irritations, vomiting and/or diarrhea. Symptoms can extend to include epileptiform seizures, and many holistic vets feel that allergies can ultimately result in chronic diseases such as arthritis, asthma, chronic urinary tract infections, inflammatory bowel disease, etc.
Interestingly, whereas dogs typically have itchy skin symptoms, a human allergic response usually produces respiratory symptoms. An estimated 10 percent of the human population may be allergic to animals (the rate for being allergic to cats is about twice as high as for dogs); a higher rate of 20 to 30 percent of individuals with asthma have pet allergies. In a nutshell, allergy is the result of an immune system that has, for one reason or another, turned against the self. Sometimes, this reaction seems instantaneous, as when a dog receives a food that contains something to which he is allergic, and he breaks out almost immediately with rashy itchy skin.