If you have read the first part of this series, you probably realize that not all ear diseases are from infection alone, and each individual may have multiple problems occurring at the same time. After performing my initial examination (which includes an examination of the rest of the body, otic cytology , +/- a culture of the ear, and hopefully an examination of the ear canal with an otoscope – if the patient allows it), a treatment plan is formulated and discussed with my client. It is important to note that in addition to the underlying medical problem, the temperament of the patient and the ability of the owner to administer treatment must be considered when deciding the best approach. However, for the sake of this discussion, let’s assume that the patient will allow therapy and the owner can administer treatment as directed.
If the extent of the presenting signs is confined to the ears, the first thing that I consider is whether or not both ears are affected. This is very important, because if both ears are affected – as is usually the case – the primary cause is not likely infectious, as developing infections in both ears at the same time is not common in dogs and cats. If infections or overgrowth of bacteria or yeast is present, it is likely secondary to another underlying disorder. Remember, when it comes to dermatologic (skin) diseases (Ears are many times included with these.), SYMMETRY = SYSTEMIC disease! The most common systemic conditions that we see affecting the ears are hypersensitivities, such as environmental or food allergies. There are other conditions that can cause symmetrical ear disease, but they are less common, so I will save those for another discussion.
Okay….on to treatment.
If the ear canals are severely swollen to the point that cleaning would be difficult and painful for the patient, I may consider oral steroids for several days in order to make topical therapy easier. If yeast are noted on cytology I will use a cleanser with an antifungal such as ketoconazole. I will fill the ear canal with the cleanser, massage the ear canals and allow the dog to shake her head. I will not clean the ears out for 5-10 minutes in order to allow sufficient contact time for the antifungal to kill the yeast. Next I will apply a light coat of an ointment based medication that has an antifungal and a steroid. I will have the owners administer the therapy once daily and have them come back for a follow-up examination in a week or so. If there is improvement, I will continue the treatment for another week and then decrease therapy to every second or third day for another 1-2 weeks. If there is no improvement, I would consider either a diet trial with a hypoallergenic diet for at least 12 weeks and/or just discontinue the topical therapy, as some dogs may have a hypersensitivity reaction to the topical medications. If there is bacterial overgrowth only, I will choose one of a few cleansers to apply based on what type of bacteria are found. I may or may not use topical steroids in these dogs initially. My priority in these cases is to treat the secondary infections first and follow up on the underlying conditions, such as allergies, once the overgrowth or infections are cleared. That approach should be taken with all dermatologic cases, not only otitis. If the otitis occurs for a few weeks during the height of allergy season, and the dog is normal the rest of the year, this is a very reasonable approach. If however, the signs occur during most or all of the year, a more aggressive approach is needed. This may include diet trials with a hypoallergenic diet, allergy testing, or other medications that would be safer for long-term use. In some cases, by the time these dogs are brought to us the changes in the ear canal are so severe that no medical approach will work. In these dogs, the pain is so severe and they cannot usually hear well at this point, that surgical procedures are recommended to provide comfort. The ability to hear may not return, but the dog (and the owner) are usually very happy due to the pain relief.
An important thing to note is that when there is a primary infection present, oral therapy used alone will not work! An strong topical antibiotic solution must be infused into the ear canal daily, sometimes for several weeks depending on the type of infection. In fact, I usually do not prescribe an oral antibiotic for these cases unless there are generalized skin infections present.
At our websites under the “Pet Care” tab, you can find a nice diagram of the ear canal and instructions on ear treatment as described above.
Go to eastmeadowvetclinic.com or sbvg.biz