• Dog's ears are composed of three main parts: the external, middle and inner ear. All three parts can be impacted by various ailments that cause itching, inflammation, infection and, in extreme circumstances, hearing impairment. In addition, external ear problems can spread to the middle and inner ear, requiring more aggressive treatment to prevent long-term problems.
  
  

Allergies

• Newman Veterinary Medical Services tells us that external ear problems affecting the pinna (the cartilage core and skin) most often originate from allergies. Dogs with allergies caused by food and environmental irritants frequently experience itching of the ear and other parts of the body. Otitis--an inflammation of the ear resulting in infection--may occur when the dog is exposed to the allergen for prolonged periods of time without treatment.
  
  

Ear Mites

• Ear mites burrow deep below the skin of the dog's ear, causing itchiness and a dark crust to form along the folds in the ear. Constant scratching eventually leads to redness and irritation.
  
  

Foreign Objects

• In some cases, a foreign object, such as a bug, blade of grass or sand, enters the ear canal. The object may cause the dog to shake his head continually in an effort to rid the object from his ear. He may also scratch his ear or rub his head on the floor to provide relief. The dog's ear skin becomes inflamed and possibly scratched as a result of his attempts to force out the object.
  
  

Tissue Mass or Tumor

• A mass of tissue or a tumor sometimes forms on the dog's ear skin. It can be either benign or cancerous. A tumor can make it difficult to keep the ear clean, which can cause infection and lead to hearing loss.