GP Thornit Ear Powder Thornit ear powder is used for ear mites and their complications - such as itching - in dogs, cats and small animals. Itchy ears are usually caused by an ear mite which also creates blobs of wax that can be seen in the ear. These blobs can also weep and smell. Simply sprinkle a small amount of Thornit ear powder onto the inside of the ear surface NOT the ear hole and massage in. Available in 20g & 100g jars.