Inflammation of the external ear canal (otitis externa) is a very common problem in dogs. The usual signs of ear problems include head shaking, smelly and dirty ears, itchiness and discharge. Bacteria and yeast are common culprits associated with ear problems. However, it is important to understand that most ear infections are due to an underlying cause. It pays to investigate what is actually causing the problem instead of just treating the symptoms.
Help! My dog has a sore ear, New Farm Vet.
There are 3 main categories of factors that contribute to ear infections and treatments for them can vary.
Primary factors:
Primary factors directly cause ear infection. Allergies such as atopic dermatitis and food allergy are most commonly associated with recurrent ear infections. Another primary factor is ear mites. It is more common to see these kinds of parasites in cats. Other factors include irritants / foreign bodies like grass seeds, dirt, sand etc.
Predisposing factors:
These factors increase the risk of an ear infection. Narrow ear canals, long ears and hairy ear canals can impair ventilation and clearance of normal secretions from the ears. It is important to note that the presence of dense hair does not mean your pooch will develop ear problems – plucking of hair from dogs not suffering from ear problems may potentially cause ear problems instead. However, if your pet has recurrent ear infection, then removal of excess hair may help. Excessive moisture, due to high humidity in different country regions or frequent swimming/bathing, may lead to disruption of the ear skin tissue, increasing the risk of an ear infection.
Perpetuating factors:
Perpetuating factors prevent the resolution of ear problems. External ear canals can progressively become narrower due to chronic unresolved ear inflammation as soft tissue within the ear canal increases/thickens. This results in stenotic ear canals. Changes in the luminal diameter, moisture level and warmth within the ear carnal can lead to disruption of ear skin tissue and increase microbial growth. The presence of bacteria and yeast usually does not induce ear problems, but can cause it when there are perpetuating factors favourable to their growth.
Stay tune for tomorrow's blog on treatment for recurring ear infection.
