Treatment of Canine Sinonasal Aspergillosis by Sinusal and Nasal Depot Therapy with Clotrimazole Under Endoscopic Guidance

Introduction:
The objective of this retrospective study was to evaluate the effectiveness of a non-invasive sinusal and nasal depot therapy of clotrimazole (1%) cream in dogs with sinonasal aspergillosis under endoscopic guidance.

Material and methods:
Rhinoscopy was performed in 10 dogs with sinonasal aspergillosis. Direct sinus access through the sinonasal ostium was possible with a flexible endoscope to allow sinuscopy. Complete debridement of fungal plaques in the frontal sinus and the nasal cavity was performed. Sinus and nasal depot therapy with clotrimazole cream was performed under endoscopic guidance. A rhinoscopic follow-up was performed monthly until the absence of fungal plaques could be determined.

Results:
Fungal plaques were seen in 100% of the frontal sinuses and in 60% of the nasal cavities. Five dogs were considered to be be cured at the first follow-up rhinoscopy, 4 after the second follow-up and 1 after the third one. Two dogs had delayed recurrence of sinonasal aspergillosis rhinoscopically assessed, 12 and 21 months after the last clotrimazole deposit respectively.

Discussion:
Endoscopic access to frontal sinus allowed complete debridement of fungal plaques before applying topic treatment. The viscosity of the clotrimazole cream provided greater persistence in the frontal sinus and nasal cavity than an antifungal solution. All the dogs were considered cured after 1, 2 or 3 depot therapies. This was consistent with the success rates reported in others studies dealing with the topical treatment of sinusal aspergillosis. When the delayed recurrences were taken into account, the success rate was 80% in this study.