|Bilateral ear canal infections are common in dogs. Ear canal neoplasia is usually associated with unilateral problems, and is uncommon in dogs.
To the best of the author`s knowledge, bilateral aural neoplasia has not been reported in dogs, and only four case reports were found in the human literature.
This report presents three dogs that had bilateral tumours in their ear canals. They were presented with bilateral otitis externa.
All three dogs exhibited tissue proliferation of both ear canals that did not respond to glucocorticoids.
Treatment consisted of total ear canal ablation, and tissues were submitted for histopathological evaluation.
Case # 1 (a 10-year-old, male cocker spaniel) was diagnosed as ceruminious gland carcinoma.
Cases # 2 and 3 were diagnosed as squamous cell carcinoma.
Case # 1 was diagnosed 4 years earlier as having keratinization disorder, which was causing its chronic ear problems.
Case # 2 (a 5-year-old, female French bulldog) was diagnosed 4 years earlier as having atopic dermatitis, which did not respond to hyposensitization, and only partially responded to glucocorticoids therapy.
Case # 3 (a 9-year-old, male German shepherd) was diagnosed by the referring veterinarian as having unilateral ear canal proliferation 2 months prior to presentation.
However, otoscopic examination showed bilateral proliferation that obstructed both canals. In summary, bilateral ear canal neoplasia should be considered in cases of nonresponsive, proliferative aural pathology.
Source: ZUR, GILA (2005): Bilateral ear canal neoplasia in three dogs. In: Veterinary Dermatology 16 (4), 276-280.