Clinical findings and outcomes of eight dogs with surgically treated frontal sinus mucoceles.

Objective: To report clinical findings and outcomes of dogs surgically treated for frontal sinus mucocele.

Study design: Short case series.

Animals: Eight dogs.

Methods: Seven of eight dogs had evidence of previous skull trauma and developed clinical signs by 10 months of age. On computed tomography, all dogs had a fluid-attenuating, expansile lesion within the frontal sinus and multicentric bone erosion. Surgical treatments comprised frontal sinusotomy and debridement, with either stenting of nasofrontal openings or removal of all sinus lining, with or without fat graft ablation.

Results: Four dogs were clinically normal 10-70 months after surgery; two of these dogs had developed swelling 1.5-3 months after surgery, which resolved within 4 months, and one temporarily developed nasal discharge 1 month after stent removal. The mucocele recurred in four dogs 1 to 9 months after surgery; three of those dogs underwent a second surgery with nasofrontal stenting. Two of those dogs were clinically normal at 6 or 20 months after the second surgery. Owners of the third dog reported intermittent swelling for 16 months after the second surgery, which was managed with guaifenesin and carprofen or prednisone. Overall, resolution occurred in one dog with debridement and fat graft ablation and in five dogs with nasofrontal stenting.

Conclusion: Young dogs with skull trauma may develop aseptic sinus mucoceles that cause facial distortion and compression of surrounding structures. Re-establishment of sinus drainage or ablation of the lining may resolve clinical signs; however, multiple surgeries may be required.