July 2013 Case of the Month
Meet Heidi, a 6 year old Yorkshire Terrier. Heidi came in for her regular grooming appointment earlier this spring. Heidi’s owners wanted to make sure the doctor examined Heidi’s ears, because she had recently been scratching them a lot and shaking her head frequently. Heidi is no stranger to having ear infections and usually develops them during the spring summer months. That day was no different. Heidi did indeed have an ear infection in both ears.
During her exam, Heidi’s ears were described as red, inflamed, pruritic (itchy), stenotic (swollen ear canal), and there was a significant amount of a thick brown discharge. A cotton swab was placed in each ear to obtain a sample of the brown discharge. The discharge was spread out on a slide using a special stain, we were able to determine one of the causes for Heidi’s ear infection: yeast!
Heidi had numerous amounts of yeast, or Malassezia, in her ears. This is a common organism found in ear infections and skin lesions. This is likely one of the major causes for Heidi’s ears to be so itchy. However, this organism is also known as an ‘opportunistic pathogen’ meaning that it was not the initial cause for the ear infection, and is actually a secondary problem.
Many dogs develop ear infections during the spring/summer months because of 2 major reasons: allergies, and increased moisture in the ear (there are certainly other causes as well, but these tend to be the most common). If a dog is prone to allergies, they tend to be itchy all over. Once the scratching starts, there is damage done to the skin (or ears) that allows things like Malassezia to set up an infection. Also, Malassezia is an organism that loves hot humid places. So if they can find a nice, cozy, moist spot in a poorly ventilated area – like an ear that has a lot of wax or hair for incubation – then they ‘set up shop.’
The key to treating these types of ear infections is 2 fold. First we need to clean the gunk out of the ears with an ear cleansing solution that also helps dry out the ear canal. Then, we apply a topical medication to kill the bugs, and soothe the irritation. In Heidi’s case, we also started her on a short course of oral steroids to reduce inflammation further and bring down the swelling in her ear canals.
There are some steps to take that can help reduce the amount of ear infections dogs get this time of year. If the cause is a known allergy, medication can be given on a routine basis to keep the pet in a comfortable state and keep them from scratching. Also, a good, thorough ear cleaning should be done every time a pet has a bath, goes swimming, or plays in the mud! The ear cleaner used should be a veterinary approved cleaning solution.
As for Heidi, her ear infection was resolved and she is reported to be doing very well at home.