Your dog gets allergies just like you do, from different foods (corn, grain, fish, chicken, beef), pollen, dander, and fleas. A dust mite allergy is caused by tiny spider-like creatures that live in our homes to eat the dander (skin and hair flakes) from our bodies. They are not visible to the naked eye, but under a microscope they look similar to a white flea, but they are actually related to the spider and have eight legs. Mites (and their waste) get onto the skin and breathed in by the lungs whether the mites are dead or alive, so just killing them is not the answer. You have to rid the entire house of the bodies and the waste they produce to make your home truly dust mite free, but it is next to impossible to do such a thing. The symptoms are red and oozing skin, rash, licking excessively, scratching, and redness and watering of the eyes and nose. If your dog has a severe reaction, it may also produce inflammation of the airway (anaphylaxis) and cause a constriction that makes it hard to breathe. Because of this, if you notice your dog sneezing, coughing, and wheezing you need to go to an animal hospital right away.
Dogs with dust mite allergies can be misdiagnosed because the symptoms are very similar to other conditions. The scratching and inflammation may be mistaken for fleas, dry skin, or chronic dermatitis when it is actually the dust mite causing the reaction. Dust mites are microscopic organisms that live in every home no matter how much you clean. In fact, it is during or after vacuuming or dusting that the allergy seems to get much worse. The main difference between dust mite allergy and other causes of itchy skin (dermatitis, dry skin, fleas) is that with dust mite allergy your dog will also have sneezing, runny eyes and nose, a cough, and possible wheezing. Though not typically documented as a problem with dust mites allergies, studies show that anaphylaxis, a life-threatening emergency causing swelling of the airway and inability to breathe, is possible. Any time that your dog is having breathing abnormalities or is in distress due to itching and scratching, a veterinary visit is needed without delay.