The veterinarian will make a diagnosis based on the clinical signs, physical exam findings, and through the use of several other diagnostic tools. One such tool is cytology, which involves taking a swab of the ears and looking at the material collected under a microscope for the presence of bacteria, yeast, mites, and other substances that might cause an infection. Bacteria and yeast are normally present in low numbers in all dogs' ears, but a large presence will lead to an ear infection.
Skin biopsies may be needed to determine any diseases such as an autoimmune disorder that could cause a skin abnormality affecting the ear. Skin scrapings may be needed to detect mites, tiny parasites that can infect the ears and cause skin diseases. X-rays of the skull can be used to examine the middle and inner ear for signs of disease. In addition, cultures of an infected ear help determine the presence and type of bacteria, as well as antibiotics that are appropriate for treatment. The majority of animals with ear problems have such pain in their ears that they cannot withstand having them examined, cleaned, cultured, or x-rayed without the use of general anesthesia.
